• 대한전기학회논문지:시스템및제어부문D
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• 제51권4호
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• pp.167-174
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• 2002

This study describes a fetal heart rate(FHR) estimation algorithm using phonogram. Using a phonogram amplifier, various fetal heart sounds are collected in a university hospital. The FHR estimation algorithms consists of a lowpass filter, decimation, envelop detection, pitch detection, and post-processing. The post-processing is the FHR decision procedure using all informations of fetal heart rates. Using the algorithm and other parameters of fetal heart sound, a fetal monitoring software was developed. This can display the original signals, the FFT spectra, FHR and its trajectory. Even though the fetal phonogram amplifier detects the fetal heart sounds well, the sound quality is not so good as the ultrasonography. In case of very week fetal heart sound, autocorrelation of it showed clear periodicity. But two main peaks in one period is an obstacle in pitch detection and peaks are not so vivid. The proposed FHR estimation algorithm showed very accurate and stable results. Since the developed software displays multiple parameters in real time and has convenient functions, it will be useful for the phonogram-style fetal monitoring device.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.181-184
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• 2004

There are reports showing that electromagnetic fields (EMFs) emitted at non-thermal levels may be associated with biological alterations in target cells. In this study it is objected to assess the potential influences of EMFs produced by cellular phones on fetal heart rate. Non Stress Test (NST) is a widely used method of fetal monitoring and assessing fetal health and well-being. Sixty volunteers with uncomplicated term pregnancies were studied by a Spacelabs AM-67 Doppler ultrasound monitor. Fetal Heart Rate recordings were obtained while there were no Cellular Phone around for 10 minutes. Afterwards, all patients were exposed to EMFs for 10 minutes. NST was performed while they were holding the CP on stand-by mode and then on dialing mode, each for 5 minutes. The recordings were analyzed with respect to baseline heart rate, accelerations and decelerations. The Wilcoxon matched-pairs signed-ranks test was used to compare these variables. The results indicate that EMFs emitted by CP do not cause any demonstrable effects on baseline FHR, acceleration or deceleration.

• 대한간호학회지
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• 제46권3호
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• pp.315-326
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• 2016

Purpose: The purpose of this cross-over experimental study was to examine effects of music intervention on maternal anxiety, fetal heart rate pattern and testing time during non-stress tests (NST) for antenatal fetal assessment. Methods: Sixty pregnant women within 28 to 40 gestational weeks were randomly assigned to either the experimental group (n=30) or control group (n=30). Music intervention was provided to pregnant women in the experimental group during NST. Degree of maternal anxiety and fetal heart rate pattern were our primary outcomes. State-trait anxiety inventory, blood pressure, pulse rate, and changes in peripheral skin temperature were assessed to determine the degree of maternal anxiety. Baseline fetal heart rate, frequency of acceleration in fetal heart rate, fetal movement test and testing time for reactive NST were assessed to measure the fetal heart rate pattern Results: The experimental group showed significantly lower scores in state anxiety than the control group. There were no significant differences in systolic blood pressure and pulse rate between the two groups. Baseline fetal heart rate was significantly lower in the experimental group than in the control group. Frequency of acceleration in fetal heart rate was significantly increased in the experimental group compared to the control group. There were no significant differences in fetal movement and testing time for reactive NST between the two groups. Conclusion: Present results suggest that music intervention could be an effective nursing intervention for alleviating anxiety during non-stress test.

• 대한의용생체공학회:의공학회지
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• 제12권3호
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• pp.209-214
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• 1991

Digital fetal monitoring system based on the personal computer combined with the digital signal processing (DSP) board was implemented. The DSP board acquires and digitally processes ultra- sound fetal Doppler signal for digital signal conditioning, rectification, low -pass filtering, autocorrealtion function calculation and its peak detection. The personal computer interfaced with the DSP board is in charge of graphic display, hardcopy, data transmission and on -line analysis of fetal heart rate change including on - line warning system, base -line estmation, acceleration, deceleration and variability. It is one of the most suitable situation to apply the DSP chip for siganl conditioning, digital filtering of ultrasound fetal Dopier signal and fetal heart rate estimation using autocorrelation technique .

• 한국인터넷방송통신학회논문지
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• 제22권3호
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• pp.111-116
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• 2022

본 연구에서는 가정에서도 임산부가 손쉽게 태아의 심장 소리를 측정할 수 있는 소형 초음파 측정기의 프로토타입 모델을 설계 제작 하였다. 태아의 심장 박동은 내장된 블루투스 스피커를 통해 확인 할 수 있다. 심장 박동 주파수에 따라 led의 색깔이 다양하게 표출된다. 초음파 진동자, 블루투스 스피커와 스마트폰이 연동된다. 간단한 심장박동 측정을 통해 태아에 발생 될 수 있는 이상 징후를 미연에 발견할 수 있음을 확인 하였다. 소아와 성인의 경우에도 급성으로 발생되는 심근경색, 심부전등과 같은 심장 이상 징후 발견을 통해 돌연사를 미연에 방지 하는 용도로 유용하게 사용할 수 있다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.320-324
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• 1996

Digital fetal monitoring system based on the personal computer combined with the digital signal processing board was implemented. The DSP board acquires and digitally processes ultrasound fetal Doppler signal for digital rectification, FIR filtering, autocorrelation function calculation, its peak detection and MEDIAN filtering. The personal computer interfaced with the DSP board is in charge of graphic display, hardcopy, data transmission and on-line analysis of fetal heart rate change including and variability. I used a recursive technique for autocorrelation function computation method and MEDIAN filter which can greatly reduce the amount of calculation and accuracy. I also implemented analysis algorithm of fetal heart rate change based on normal fetal sample data in order to exact diagnosis.

• 전자공학회논문지B
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• 제31B권2호
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• pp.80-87
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• 1994

Fetal monitoring is a routine procedure to obtain a record of physiologic functions during pregnancy and labor. It is required to determine fetal heart frequency accurately. There are various types of fetal heart rate(FHR) determination and the most frequently applied method is transabdominal Doppler ultrasound. However, in the case of weak or noise corrupted Doppler ultrasound signals, conventional peak detections and the autocorrelation function method have many difficulties to determine FHR precisely. Also the autocorrelation function is effected by threshold level and window size. To solve these problems, the high resolution pitch determination algorinthm is introduced to detect FHR from Doppler ultrasound signals. This scheme digitally processes Doppler ultrasound signal for digital rectification, envelope detection, decimation and correlation calculation of two interconnected segments and then FHR is determined by its maximal value. Even in the case of a greatly smeared noise signal, this algorithm is able to search FHR more accurately than autocorrelation function by means of compensating FHR with a constant correlation threshold. This algorithm is simulated by 386-MATLAB on PC 486/DX and verified that it is superior to the autocorrelation function method.

• 전자공학회논문지
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• 제49권9호
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• pp.328-334
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• 2012

산전 및 분만 중 연속적인 태아감시는 임상의에게 태아의 안녕 평가하는데 필요하다. 또한 태아의 심장박동은 임신 중 태아의 건강을 평가하는 중요한 파라미터이다. 초음파 도플러는 태아 심박을 비관혈적으로 측정할 수 있는 방법으로 매우 유용하다. 그러나 현재 임상에서 널리 쓰이고 있음에도 불구하고, 태아 심박을 검출하는데 있어서 제한적인 정보만 제공할 뿐만 아니라 검출 오류에 대한 문제가 완전히 해결되지 못하고 있다. 본 연구의 목적은 태아의 초음파 도플러 신호로부터 태아 심박을 검출하는 알고리즘을 간단한 방법으로 개선하고자 한다. 신호 주기를 검출하는데 가장 널리 쓰이는 자기상관함수의 수정된 함수를 제안하고, 신호의 주기를 찾기 위해 설정하는 데이터 분석 구간의 크기와 이동 간격을 가변하도록 하였다. 제안된 방법은 실제 산모에게서 측정된 데이터에 적용하여 태아 심박의 beat-to-beat 검출이 가능함을 확인하였으며, 태아 심전도 신호와도 비교하였다. 제안하는 방법은 간단하면서도 효과가 있으므로 실제 장비에 적용될 수 있을 것으로 기대된다.

• 한국정보전자통신기술학회논문지
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• 제2권3호
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• pp.9-15
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• 2009

분만시 국내에서 영아 사망률은 약 1%에 이르고, 태아의 질병 발생과 사망은 계속적으로 일어나고 있으므로 저가의 태아 모니터링기술의 개발이 절실하다. 이를 위하여 본 연구에서는 임산부의 복부로부터 태아의 움직임과 심음을 검출할 수 있는 증폭기를 설계하여 고성능 태아 포노그램용 전자청진장치를 개발하고자 한다. 장치로부터 검출된 태아의 청진 신호는 듣거나 녹음할 수 있으며, PC에서 태아의 심음을 분석할 수도 있다. 개발된 증폭기를 이용하여 잡음에 노출된 일반 대학병원 환경에서 30명의 임산부를 대상으로 임상실험을 수행한 결과, 개발된 증폭기는 저잡음, 고이득의 특성을 나타내고, 임산부 중에서 빠른 경우 22주에서도 태아의 심음을 검출할 수 있었고, 심음의 주기검출이 가능하였다.

• 여성건강간호학회지
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• 제16권4호
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• pp.336-347
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• 2010

Purpose: The purpose of this study was to identify the effect of relaxation therapy on state anxiety, preterm labor stress, blood pressure, skin temperature, pulse rate of pregnant women with preterm labor and heart rate of their babies. Methods: The participants were 55 pregnant women with preterm labor who hospitalized from May, 2009 to January, 2010. 29 participants were assigned to experimental group and the other 26 participants to control group. All of them were not have any other complications except preterm labor. The relaxation therapy was applied to the experimental group for 5 days. Data were analyzed by the SPSS/WIN 14.0 program. Results: The state anxiety score and the preterm labor stress score of experimental group were statistically significant lower than those of control group. In addition, the systolic and diastolic blood pressure, pulse rate of experimental group were statistically lower than those of control group. The skin temperature of experimental group was higher than that of control group. However, the fetal heart rate of experimental group was not statistically significant lower than fetal heart rate of control group. Conclusion: From these findings, it is concluded that relaxation therapy may be an effective nursing intervention for pregnant women with preterm labor.