• 제목/요약/키워드: R-R interval

검색결과 979건 처리시간 0.03초

안드로이드 기반 스마트폰 연동 심박변이도 추정 (Estimation of Heart Rate Variability with an Android Smart Phone Platform)

  • 김정환;신승원;김현태;윤태호;김경섭;이정환;엄광문
    • 전기학회논문지
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    • 제61권6호
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    • pp.865-871
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    • 2012
  • In this study, ambulatory electrocardiogram(ECG) signal and the rhythms of heart beats are visualized in terms of R-R intervals and Heart Rate Variability(HRV) in the environment of an android plaform. With this aim, Graphical User Interface(GUI) is implemented by executing multi-thread Java programming modules including ECG, heart-beats, tachogram and visualization unit. ECG signals are acquired in an android device by receiving the data from ambulatory ECG sensory system. Finite Impulse Response(FIR) filters are implemented to eliminate the baseline wandering noises contained in the ambulatory signals and DC-offset level in R-R interval data. With simulating the normal or stress emotional state of a subject, we can find the fact that HRV can be successfully estimated and visualized in an android smart phone platform.

유도 저혈압하 양악 교정술 시 Nicardipine과 Remifentanil의 혈역학적 비교 (The Comparison of the Effects of Nicardipine and Remifentanil on Fluctuation of Blood Pressure during Controlled Hypotension)

  • 김은수;황부영;김철홍
    • 대한치과마취과학회지
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    • 제10권2호
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    • pp.166-171
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    • 2010
  • Background: Controlled hypotension is used to reduce bleeding and improve surgical conditions during surgery. Nicardipine and remifentanil have been used to induce controlled hypotension in healthy patients. This study compared controllability of nicardipine and remifentanil on hemodynamic stability during controlled hypotension. Methods: Forty healthy patients scheduled for orthognathic two jaw surgery were randomly allocated to nicardipine (group N) and remifentanil (group R) group. After induction of anesthesia, group N (n = 20) was infused with nicardipine to induce hypotension and group R (n = 20) was infused with remifentanil. Mean arterial pressure (MAP) and heart rate (HR) were measured over 5 minute interval. Surgical field rating and blood loss were measured after surgery. Results: HR was lower in group R than group N. MAP was maintained at 50-60 mmHg during controlled hypotension but the fluctuation of blood pressure and HR were more frequent in group N than group R. There were no significant differences in the surgical field rating and blood loss between the groups. Conclusions: Nicardipine and remifentanil enabled controlled hypotension and provided good surgical conditions, but the fluctuation of hemodynamic parameters was more frequent in nicardipine group.

정상 영아 및 장애 위험 영아의 한국 Bayley 영유아발달검사(K-BSID-II) 수행 비교 : 3년 종단자료분석 (K-BSID-II Performance in Normal and High Risk Infants : A Three Year Longitudinal Data Analysis)

  • 박혜원
    • 아동학회지
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    • 제27권1호
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    • pp.153-166
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    • 2006
  • Stability of the Korean Bayley Scale of Infant Development-II was tested in 305 infants by two measurements of varying intervals over a span of 5-36 months. Stability of K-BSID-II performance was r=.62(p<.01), r=.08(p<.18), r=.69(p<.01), r=.18(p<.01) for mental scale raw scores, mental scale index scores (MDI), psycho-motor scale raw scores and psycho-motor scale index scores(PDI), respectively. Stability was higher for the shorter test-retest interval group. Correlations between raw scores among infants with retest intervals of more than 2 years were stable on both mental and psycho-motor scales. MDI showed higher stability among high-risk infants than normal infants while PDI showed higher stability among normal infants. Testers and researchers should use both raw scores and index scores for better interpretations.

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초음파 섹터 스캐너를 위한 디지털 스캔 변환 기법 (Digital Scan Converter Algorithm for Ultrsound Sector Scanner)

  • 김근호;오정환
    • 대한의용생체공학회:의공학회지
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    • 제17권4호
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    • pp.469-478
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    • 1996
  • In the conventional digital ultrasound scanner, the reflected signal is sampled either in polar coordinates of R-$\theta$ method, or in Cartesian coordinates of uniform ladder algorithm (ULA). The R-$\theta$ scan method necessitates a coordinate transform process which makes hardware complex in comparison with ULA scan mrthoA In spite of this complexity, R-$\theta$ method has a good resolution in ultrasonographic (US) image, since scan direction of the US imaging is a radial direction. In this paper, a new digital scan converter is proposed, which is named the radius uniform ladder algorithm (RULA). The RULA has the rome scan direction as the US scanning in the radial direction and as the display space in the $\theta$ direction. In tllis new approach, sampled points we uniformly distributed in each horizontal line i.n well as in each radial ray so that the data are displayed in the Cartesian coordinates by the 1-D interpolation process. The propped algorithm has an uniform resolution in the periphery and the center field in comparison with equi-angle ULA and equi-interval ULA. To extend the scan angle, concentric square raster sampling (CSRS) is adopted with reduction of discontinuities on the junctions between horizontal scan and vertical scan. The discontinuities are reduced by using the hmction filtering along the $\theta$ direction.

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Reproducibility of a food frequency questionnaire: Korea Nurses' Health Study

  • Song, Sihan;Kim, Bohye;Pang, Yanghee;Kim, Oksoo;Lee, Jung Eun
    • Nutrition Research and Practice
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    • 제16권1호
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    • pp.106-119
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    • 2022
  • BACKGROUND/OBJECTIVES: This study aimed to examine the reproducibility of food frequency questionnaires (FFQs) designed for young female nurses in the Korea Nurses' Health Study. SUBJECTS/METHODS: The reproducibility of web-based, self-administered FFQs was evaluated among 243 Korean female nurses. The first FFQ (FFQ1) was administered from March 2014 to February 2019 and the second FFQ (FFQ2) from November 2019, with a mean interval of 2.8 years between the FFQs (range, 9 months-5.6 years). Pearson and Spearman correlation coefficients (r values) and quartile agreements between FFQ1 and FFQ2 were calculated for intakes of energy, nutrients, and foods. RESULTS: Pearson correlation coefficients ranged from 0.41 to 0.55 (median r = 0.51) for energy and raw nutrients and from 0.16 to 0.46 (median r = 0.36) for energy-adjusted nutrients. Spearman correlation coefficients ranged from 0.25 to 0.72 (median r = 0.41) for food items. The percentages of women who were classified into the same or adjacent quartile were 77% to 84% (median = 82%) for raw nutrients and 69% to 86% (median = 78%) for foods. CONCLUSIONS: The results indicated that the web-based FFQ used in the Korea Nurses' Health Study has acceptable reproducibility.

한우 송아지 이유시기가 증체, 사료섭취량, 질병발생 및 어미소의 번식효율에 미치는 영향 (Effects of Weaning Age on Growth Performance, Feed Intake, Disease Occurrence of Hanwoo Calves and Reproductive Efficiency of Dams)

  • 권응기;박병기;조영무;한만희;최창용;이명식
    • Journal of Animal Science and Technology
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    • 제49권2호
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    • pp.239-244
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    • 2007
  • 본 연구는 한우 송아지의 이유시기별 발육, 사료섭취량, 질병발생 및 어미소의 번식효율에 미치는 영향을 조사하기 위하여 수행되었다. 시험축은 축산연구소에서 자체 생산된 한우 송아지 60두를 공시하여 이유시기별로 조기이유(EW, 생후 3개월령)와 관행이유(NW, 생후 4개월령)에 각각 29 및 31두씩 배치하여 두 개의 시험구를 두었다. 송아지의 포유기 및 이유후 체중과 일당증체량은 이유시기에 따른 차이는 없었다(p>0.05). 또한 인공유, 목건초, 건물, 조단백질 및 TDN 섭취량도 이유시기에 의한 영향은 없었다(p>0.05). 어미소의 분만간격은 관행이유 시험구에 비해 조기이유 시험구에서 23일 정도 단축되는 경향을 보였다(p>0.05). 한편 이유시기에 따른 발생 질병의 종류와 발병율은 시험구간 차이가 없는 것으로 조사되었다. 따라서 이유시기 단축이 한우 송아지의 성장, 사료섭취량 및 질병 발생에 미치는 부의 영향은 없었을 뿐만 아니라 어미소의 분만간격을 단축시키는데 효과가 있는 것으로 사료된다.

리피토정® (아토르바스타틴 20 mg)에 대한 아토르바정®의 생물학적동등성 (Bioequivalence of Atorva Tablet® to Lipitor Tablet® (Atorvastatin 20 mg))

  • 임현균;이태호;이재현;염정록;송진호;한상범
    • Journal of Pharmaceutical Investigation
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    • 제38권2호
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    • pp.135-142
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    • 2008
  • The present study describes the evaluation of the bioequivalence of two atorvastatin tablets, Lipitor $Tablet^{(R)}$ (Pfizer, reference drug) and Atorva $Tablet^{(R)}$ (Yuhan, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Forty-nine healthy male Korean volunteers received each medicine at the atorvastatin dose of 40 mg in a $2{\times}2$ crossover study with a two weeks washout interval. After drug administration, serial blood samples were collected at a specific time interval from 0-48 hours. The plasma atorvastatin concentrations were monitored by an high performance liquid chromatography -tandem mass spectrometer (LC-MS/MS) employing electrospray ionization technique and operating in multiple reaction monitoring (MRM) and positive ion mode. The total chromatographic run time was 4.5 min and calibration curves were linear over the concentration range of 0.1-100 ng/mL for atorvastatin. The method was validated for selectivity, sensitivity, linearity, accuracy and precision. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 48hr) was calculated by the linear log trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were complied trom the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for Atorva $Tablet^{(R)}$ / Lipitor $Tablet^{(R)}$ were ${\log}\;0.9413{\sim}{\log}\;1.0179$ and ${\log}\;0.831{\sim}{\log}\;1.0569$, respectively. These values were within the acceptable bioequivalence intervals of ${\log}\;0.8{\sim}{\log}\;1.25$. Based on these statistical considerations, it was concluded that the test drug, Atorva $Tablet^{(R)}$ was bioequivalent to the reference drug, Lipitor $Tablet^{(R)}$.

산소와 색채 조명 자극의 조합이 스트레스 완화에 미치는 효과: 심리 및 자율신경계 반응을 중심으로 (Effects of the Combination of Oxygen and Color Light on Stress Relaxation: Psychological and Autonomic Responses)

  • 장은혜;김아영;장용원;김보성;최용복;김승철;이상곤;김승환
    • 감성과학
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    • 제22권1호
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    • pp.55-64
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    • 2019
  • 스트레스는 자율신경계 반응의 변화를 수반하며, 특히 심박변이도 지표는 스트레스에 의한 자율신경계의 활동을 반영하는 양적 지표로 사용된다. 본 연구에서는 스트레스 완화를 위한 산소와 색채 조명의 복합 자극이 제시되는 동안 자율신경계 반응의 변화를 확인하였다. 42명의 실험참가자는 지난 2주 동안 경험한 스트레스에 대한 증상들을 스트레스 반응 척도에 평가하였다. 스트레스 평가 후, 실험참가자는 복합 자극을 제시받았고, 자극 제시 전과 후, 그리고 자극이 제시되는 동안 심전도 신호가 기록되었다. 자극 조건은 30% 농도의 산소와 백색 조명, 산소와 주황색 조명과 산소와 파란색 조명의 조합의 세 가지로 구성되었다. 심박률(HR), R-R간격의 표준편차(SDNN), 연속한 R-R 간격 차이 값의 평균제곱근(RMSSD)과 심박변이도의 저주파 성분(LF), 고주파 성분(HF), 그리고 LF와 HF의 비율을 심박변이도 지표로 추출하였다. 이들 지표는 자극 제시 전과 후의 평균을 비교하는데 활용되었다. 결과는 자극 조건이 제시되고 난 후, HR과 LF/HF ratio의 유의한 감소를 보여주었다. 특히, 산소와 파란색 조명이 제시된 조건에서 다른 두 조건보다 유의하게 큰 RMSSD와 HF의 증가 및 LF/HF ratio의 감소가 나타났다. 이는 30% 농도의 산소와 파란색 조명의 조건이 부교감신경의 활성화에 의한 자율신경의 균형을 유발하여 스트레스 이완에 가장 효과적임을 보여주었다.

STUDY OF COMPARATIVE MILK PRODUCTION AND REPRODUCTION OF JERSEY CATTLE UNDER USA AND PAKISTAN CONDITIONS

  • Nawaz, M.;Anwar, M.;Mirza, M.A.;Nawaz, R.
    • Asian-Australasian Journal of Animal Sciences
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    • 제6권4호
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    • pp.549-553
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    • 1993
  • In 1985, fifty Jersey cows were imported to Pakistan from United States of America (USA). This paper compares milk production and reproduction performance of imported cows and their daughters under USA and Pakistan conditions. The imported cows which had yielded 5,858 kg, of milk (305 d lactation) in the USA produced only 3,192 kg, at NARC. The milk production of their daughters averaged 2,617 kg, being 22% lower than their mothers under the same environment at NARC. Year and season of calving had no significant effects on milk production. Average milk production of the first lactation was 10% lower than the mean of the second, third and fourth lactations, but, the differences between lactation means were non-significant. Mean calving interval in the USA was 385 days, whereas the same cows had a longer (p<.01) calving interval of 490 days at NARC. The calving interval of the daughters was longer (452 d; p<.01) than their mothers calving interval in the USA, and shorter (p<.01) than their mothers calving interval in Pakistan. The low age at first calving suggests that locally born Jersey cows were not reproductively disadvantaged by the local environment and nutrition, suggesting the adaptability of this breed in the new environment.

레이저 변위계를 이용한 암석 절리면의 3차원 거칠기 측정기 개발 (Development of a 3D Roughness Measurement System of Rock Joint Using Laser Type Displacement Meter)

  • 배기윤;이정인
    • 터널과지하공간
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    • 제12권4호
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    • pp.268-276
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    • 2002
  • In this study, a 3D coordinate measurement system equipped with a laser displacement meter for digitizing rock joint surface was established and the digitized data were used to calculate several roughness parameters. The parameters used in this study were micro avenge inclination $angle(i_{ave})$, average slope of joint $asperity(SL_{ ave})$, root mean square of $i-angle(i_{rms})$, standard deviation of height(SDH), standard deviation of $i-angle(SD_i)$, roughness profile $index(R_P)$, and fractal dimension(D). The relationships between the roughness parameters based on the digitzation of the surface profile were analyzed. Since the measured value varied according to the degree of reflection and the variation of colors at the measuring point, rock joint surface was painted in white to minimize the influence of the surface conditions. The comparison of the measured values and roughness parameters before and after painting revealed the better consequence from measurement on the painted surfaces. Also, effect of measuring interval was studied. As measured interval was increased, roughness parameters were exponentially decreased. The incremental sequence of degree of decrease was $SDH\; i_{ave},\; i_{rms},\; SD_i,\;and\; R_ p-1$. As a result of comparison of parameters from pin-type measurement system and laser type measurement system, all value of parameters were higher when laser-type measurement system was used, except SDH.