Development of Algorithm for Estimation of Gestational Age using each Variable of Fetal Heart Rate / 대한산부인과학회잡지

OBJECTIVE: The objective of this study is to estimate gestational age by using FHR parameters after linear and nonlinear analysis of FHR data. Linear spectral decomposition has a limit to describe and analyze the nonlinear and complex physiological nature. Random processing and chaotic analysis assist to quantify some patterned energies, interaction of the physiological system in body system, which the constancy is preserved, and complexity of physical cardiovascular system. But there are no great development of new device which notify fetal age. METHODS: From March 1995 to December 2000, 2,548 cases who received NST during antenatal visit were included in this study. Among these cases, 1000 cases were sampled randomly. We divided this cases into a study and a control group, 500 cases for model building set and the other 500 cases for validation set. Each FHR parameters such as baseline FHR, variability (AMP, MMR), acceleration & deceleration (15 bpm-15 seconds), loss of signal, the number of fetal movement were analysed by using our own computerized HYFM-I, II software system. The linear and non-linear analysis of FHR were done after extracting approximate entropy (ApEn) value. Finally, we performed regression analysis and extract an equation for estimation of gestational weeks using bootstrap method. RESULTS: We extract a following equation using above study method: Log(GA)=5.870-0.051(Sloss*)-0.065(Mean FHR*)+0.049(Mean FHR*)2-0.058(FM*)+0.048(AMP*)2+0.121(A1515*)-0.031(A1515*)2+0.036(ApEn*)2. CONCLUSIONS: Accurate dating of pregnancy, namely gestational week is very important for antenatal diagnosis in the field of perinatal medicine. This study will propose scientific research results which are useful for studying normal and morbid generating physiological fetal condition. We extract an appropriate equation for estimation of gestational weeks only using FHR parameters. We hope to compare our result with other authors' results in the near future.

Development of Algorithm for Estimation of Gestational Age using each Variable of Fetal Heart Rate / 대한산부인과학회잡지

OBJECTIVE: The objective of this study is to estimate gestational age by using FHR parameters after linear and nonlinear analysis of FHR data. Linear spectral decomposition has a limit to describe and analyze the nonlinear and complex physiological nature. Random processing and chaotic analysis assist to quantify some patterned energies, interaction of the physiological system in body system, which the constancy is preserved, and complexity of physical cardiovascular system. But there are no great development of new device which notify fetal age. METHODS: From March 1995 to December 2000, 2,548 cases who received NST during antenatal visit were included in this study. Among these cases, 1000 cases were sampled randomly. We divided this cases into a study and a control group, 500 cases for model building set and the other 500 cases for validation set. Each FHR parameters such as baseline FHR, variability (AMP, MMR), acceleration & deceleration (15 bpm-15 seconds), loss of signal, the number of fetal movement were analysed by using our own computerized HYFM-I, II software system. The linear and non-linear analysis of FHR were done after extracting approximate entropy (ApEn) value. Finally, we performed regression analysis and extract an equation for estimation of gestational weeks using bootstrap method. RESULTS: We extract a following equation using above study method: Log(GA)=5.870-0.051(Sloss*)-0.065(Mean FHR*)+0.049(Mean FHR*)2-0.058(FM*)+0.048(AMP*)2+0.121(A1515*)-0.031(A1515*)2+0.036(ApEn*)2. CONCLUSIONS: Accurate dating of pregnancy, namely gestational week is very important for antenatal diagnosis in the field of perinatal medicine. This study will propose scientific research results which are useful for studying normal and morbid generating physiological fetal condition. We extract an appropriate equation for estimation of gestational weeks only using FHR parameters. We hope to compare our result with other authors' results in the near future.

The analysis of FHR parameters, approximate entropy and canonical correlation of fetuses with mild baseline tachycardia / 대한산부인과학회잡지

OBJECTIVE: This study was to determine differences of fetal heart rate (FHR) parameters, approximate entropy, canonical correlation coefficient and perinatal outcome between fetuses with mild baseline tachycardia (FHR range : 161-180 bpm) and fetuses with normal baseline FHR. METHODS: Using our own software developed by Hanyang University Hospital in Korea, non-stress tests were performed for 20 minutes and cases were divided into two groups; mild tachycardia group (FHR range ; 161-180 bpm, 100 cases) and normal group (FHR ranges ; 120-160 bpm, 197 cases). And then, we analyzed various FHR parameters, approximate entropy, adjusted canonical correlation coefficient and perinatal outcome in each group. RESULTS: Perinatal outcomes between two groups were not significant. However, mean minute range (MMR) was lower and the number of deceleration (15 bpm for 15 sec, more than one) was significantly higher in fetuses with mild tachycardia than normal group (p<0.05). The apprximate entropy and canonical correlation coefficient showed respectively 0.77+/-0.02, 0.45+/-0.06 in mild tachycardia group and 0.80+/-0.01, 0.43+/-0.07 in normal group, there were no significant differences. CONCLUSIONS: The results showed that mild baseline tachycardia in this range were not associated with an increase in the incidence of adverse perinatal outcome, although decreased MMR and increased number of deceleration in mild tachycardia group may suggest hidden subtle change of FHR parameters. Fetuses with mild tachycardia were not different irregularity of FHR quantified by approximate entropy from normal fetuses and were also similar tendency to correlation with perinatal outcome by adjusted canonical correlation coefficient, which is a multivariate extension of the univariate correlation analysis.

The analysis of FHR parameters, approximate entropy and canonical correlation of fetuses with mild baseline tachycardia / 대한산부인과학회잡지

OBJECTIVE: This study was to determine differences of fetal heart rate (FHR) parameters, approximate entropy, canonical correlation coefficient and perinatal outcome between fetuses with mild baseline tachycardia (FHR range : 161-180 bpm) and fetuses with normal baseline FHR. METHODS: Using our own software developed by Hanyang University Hospital in Korea, non-stress tests were performed for 20 minutes and cases were divided into two groups; mild tachycardia group (FHR range ; 161-180 bpm, 100 cases) and normal group (FHR ranges ; 120-160 bpm, 197 cases). And then, we analyzed various FHR parameters, approximate entropy, adjusted canonical correlation coefficient and perinatal outcome in each group. RESULTS: Perinatal outcomes between two groups were not significant. However, mean minute range (MMR) was lower and the number of deceleration (15 bpm for 15 sec, more than one) was significantly higher in fetuses with mild tachycardia than normal group (p<0.05). The apprximate entropy and canonical correlation coefficient showed respectively 0.77+/-0.02, 0.45+/-0.06 in mild tachycardia group and 0.80+/-0.01, 0.43+/-0.07 in normal group, there were no significant differences. CONCLUSIONS: The results showed that mild baseline tachycardia in this range were not associated with an increase in the incidence of adverse perinatal outcome, although decreased MMR and increased number of deceleration in mild tachycardia group may suggest hidden subtle change of FHR parameters. Fetuses with mild tachycardia were not different irregularity of FHR quantified by approximate entropy from normal fetuses and were also similar tendency to correlation with perinatal outcome by adjusted canonical correlation coefficient, which is a multivariate extension of the univariate correlation analysis.