• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.4
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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.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.3
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• pp.9-15
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• 2009

During delivery, fetal death rate is about 1%. Since fetal death or infection have been continuously occurred, low cost fetal monitoring techniques are required. This study proposes an electronic stethoscope system for fetal phonogram by developing an amplifier to detect fetal movement and heart sound from abdomen of the pregnant woman. Using the electronic stethoscope, it is possible to listen or record the fetal sound and to analyze or store the digitized signal. Through the performance test using the developed system with 30 pregnant women in university hospital, it was found that the developed amplifier showed low noise, high performance. The system can detect heart sound and periods of heartbeats of a 22-week fetus.