Signal processing and display—cardiotocographs

Carter, Michael C.

doi:10.1111/j.1471-0528.1993.tb10631.x

Cited by 20 publications

(19 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The narrow beam transducer worked in pulsed Doppler mode at a frequency of 1 MHz. On standard setup, the raw signal was processed by an autocorrelation method into acoustic output signals18, 19. The output signal was then amplified and transformed into digital information.…”

Section: Methodsmentioning

confidence: 99%

Dynamic free‐hand three‐dimensional fetal echocardiography gated by cardiotocography

Herberg

Goldberg

Breuer

2003

Ultrasound in Obstet & Gyne

View full text Add to dashboard Cite

show abstract

Section: Methodsmentioning

confidence: 99%

Dynamic free‐hand three‐dimensional fetal echocardiography gated by cardiotocography

Herberg

Goldberg

Breuer

2003

Ultrasound in Obstet & Gyne

View full text Add to dashboard Cite

show abstract

“…Subsequently, after amplification, digitalization, and filtration (STAN Service Manual, 2005), MHR signal was exported from the STAN monitor into the Omniview-SisPorto® 3.5 system (Speculum, Lisbon, Portugal), at a sampling rate of 4 Hz (Ayres-de-Campos, Sousa, Costa, & Bernardes, 2008;Pinto et al, 2014). In order to calculate the heart period, a RR interval was converted to the nearest quarter of a beat, in beats per minute (Carter, 1993). With the objective to overcome signal loss episodes and artifacts, an algorithm for FHR preprocessing described by Gonçalves, Rocha, Ayres-de-Campos, and Bernardes (2006) was used.…”

Section: Data Acquisitionmentioning

confidence: 99%

Simultaneous monitoring of maternal and fetal heart rate variability during labor in relation with fetal gender

Gonçalves

Fernandes

Pinto

et al. 2017

Developmental Psychobiology

View full text Add to dashboard Cite

Male gender is considered a risk factor for several adverse perinatal outcomes. Fetal gender effect on fetal heart rate (FHR) has been subject of several studies with contradictory results. The importance of maternal heart rate (MHR) monitoring during labor has also been investigated, but less is known about the effect of fetal gender on MHR. The aim of this study is to simultaneously assess maternal and FHR variability during labor in relation with fetal gender. Simultaneous MHR and FHR recordings were obtained from 44 singleton term pregnancies during the last 2 hr of labor (H H ). Heart rate tracings were analyzed using linear (time- and frequency-domain) and nonlinear indices. Both linear and nonlinear components were considered in assessing FHR and MHR interaction, including cross-sample entropy (cross-SampEn). Mothers carrying male fetuses (n = 22) had significantly higher values for linear indices related with MHR average and variability and sympatho-vagal balance, while the opposite occurred in the high-frequency component and most nonlinear indices. Significant differences in FHR were only observed in H with higher entropy values in female fetuses. Assessing the differences between FHR and MHR, statistically significant differences were obtained in most nonlinear indices between genders. A significantly higher cross-SampEn was observed in mothers carrying female fetuses (n = 22), denoting lower synchrony or similarity between MHR and FHR. The variability of MHR and the synchrony/similarity between MHR and FHR vary with respect to fetal gender during labor. These findings suggest that fetal gender needs to be taken into account when simultaneously monitoring MHR and FHR.

show abstract

“…Then, as detection of the electrocardiogram R wave is generally not difficult, simple R wave detection is performed. The heart period is calculated as the RR interval and converted to the nearest FHR integer, in beats per minute (bpm) [8,11,20].…”

Section: Data Acquisitionmentioning

confidence: 99%

Linear and nonlinear fetal heart rate analysis of normal and acidemic fetuses in the minutes preceding delivery

et al. 2006

View full text Add to dashboard Cite

Linear and nonlinear fetal heart rate (FHR) indices, namely mean FHR, interval index (II), very low, low and high frequencies, approximate (ApEn) and sample entropy (SampEn), were computed, immediately before delivery, in the initial and final FHR tracing segments, from 48 normal, 10 mildly acidemic and 10 moderate-to-severely acidemic fetuses. Progression of labor was associated with a significant increase in linear frequency domain indices whereas nonlinear indices were significantly decreased. Moderate-to-severe fetal acidemia was associated with a significant decrease in nonlinear indices. The best discrimination between moderate-to-severe acidemic fetuses and the remaining cases was obtained combining II and ApEn(2,0.15), with a specificity of 71% and a sensitivity of 80%. These findings support the hypothesis of increased autonomic nervous system activity in the final minutes of labor and of decreased central nervous system activity, both in the final minutes of labor and in moderate-to-severe acidemic fetuses.

show abstract

Signal processing and display—cardiotocographs

Cited by 20 publications

References 8 publications

Dynamic free‐hand three‐dimensional fetal echocardiography gated by cardiotocography

Dynamic free‐hand three‐dimensional fetal echocardiography gated by cardiotocography

Simultaneous monitoring of maternal and fetal heart rate variability during labor in relation with fetal gender

Linear and nonlinear fetal heart rate analysis of normal and acidemic fetuses in the minutes preceding delivery

Contact Info

Product

Resources

About