Towards higher accuracy and better noise-tolerance for fetal heart rate monitoring using Doppler ultrasound

Lee, Chang Su; Mašek, Martin; Lam, Chiou Peng; Tan, Ken Seng

doi:10.1109/tencon.2009.5395885

Cited by 13 publications

(9 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The optimal value of S was searched in a range from 1/15 to 1/2, which means that an average number of measurements per interval was between 2 and 15. Application of adaptive window reduced the effect of periodicity averaging as well as computational complexity of the algorithm [ 17 ], whereas repeated AF calculation during a given cardiac cycle improved the noise immunity, and as a consequence the accuracy of measurement [ 18 ].…”

Section: Methodsmentioning

confidence: 99%

A novel technique for fetal heart rate estimation from Doppler ultrasound signal

et al. 2011

View full text Add to dashboard Cite

BackgroundThe currently used fetal monitoring instrumentation that is based on Doppler ultrasound technique provides the fetal heart rate (FHR) signal with limited accuracy. It is particularly noticeable as significant decrease of clinically important feature - the variability of FHR signal. The aim of our work was to develop a novel efficient technique for processing of the ultrasound signal, which could estimate the cardiac cycle duration with accuracy comparable to a direct electrocardiography.MethodsWe have proposed a new technique which provides the true beat-to-beat values of the FHR signal through multiple measurement of a given cardiac cycle in the ultrasound signal. The method consists in three steps: the dynamic adjustment of autocorrelation window, the adaptive autocorrelation peak detection and determination of beat-to-beat intervals. The estimated fetal heart rate values and calculated indices describing variability of FHR, were compared to the reference data obtained from the direct fetal electrocardiogram, as well as to another method for FHR estimation.ResultsThe results revealed that our method increases the accuracy in comparison to currently used fetal monitoring instrumentation, and thus enables to calculate reliable parameters describing the variability of FHR. Relating these results to the other method for FHR estimation we showed that in our approach a much lower number of measured cardiac cycles was rejected as being invalid.ConclusionsThe proposed method for fetal heart rate determination on a beat-to-beat basis offers a high accuracy of the heart interval measurement enabling reliable quantitative assessment of the FHR variability, at the same time reducing the number of invalid cardiac cycle measurements.

show abstract

Section: Methodsmentioning

confidence: 99%

A novel technique for fetal heart rate estimation from Doppler ultrasound signal

et al. 2011

View full text Add to dashboard Cite

show abstract

“…This format significantly differs from that available at the output of a fetal monitor—the FHR values evenly spaced at every 250 ms. This measurement period has been established to be not longer than the shortest physiologically allowed heart cycle, however with characteristic information redundancy for low FHR values (e.g., the FHR value equal to 50 bpm is represented by four duplicated subsequent values; Lee et al, 2009 ; Goncalves et al, 2013 ).…”

Section: Methodsmentioning

confidence: 99%

“…However, the autocorrelation function does not detect the consecutive heart beats but only determines the instantaneous periodicity of the US signal envelope which corresponds to cardiac cycle being measured. This leads to effect of averaging of neighboring cardiac cycles and thus decreasing of FHR determination accuracy in relation to fetal electrocardiography (Lee et al, 2009 ; Voicu et al, 2010 ). The obtained FHR signal is provided by the bedside monitor as the trace in a printout with established time scale of 1, 2, or 3 cm/min.…”

Section: Introductionmentioning

confidence: 99%

Is Abdominal Fetal Electrocardiography an Alternative to Doppler Ultrasound for FHR Variability Evaluation?

et al. 2017

View full text Add to dashboard Cite

Great expectations are connected with application of indirect fetal electrocardiography (FECG), especially for home telemonitoring of pregnancy. Evaluation of fetal heart rate (FHR) variability, when determined from FECG, uses the same criteria as for FHR signal acquired classically—through ultrasound Doppler method (US). Therefore, the equivalence of those two methods has to be confirmed, both in terms of recognizing classical FHR patterns: baseline, accelerations/decelerations (A/D), long-term variability (LTV), as well as evaluating the FHR variability with beat-to-beat accuracy—short-term variability (STV). The research material consisted of recordings collected from 60 patients in physiological and complicated pregnancy. The FHR signals of at least 30 min duration were acquired dually, using two systems for fetal and maternal monitoring, based on US and FECG methods. Recordings were retrospectively divided into normal (41) and abnormal (19) fetal outcome. The complex process of data synchronization and validation was performed. Obtained low level of the signal loss (4.5% for US and 1.8% for FECG method) enabled to perform both direct comparison of FHR signals, as well as indirect one—by using clinically relevant parameters. Direct comparison showed that there is no measurement bias between the acquisition methods, whereas the mean absolute difference, important for both visual and computer-aided signal analysis, was equal to 1.2 bpm. Such low differences do not affect the visual assessment of the FHR signal. However, in the indirect comparison the inconsistencies of several percent were noted. This mainly affects the acceleration (7.8%) and particularly deceleration (54%) patterns. In the signals acquired using the electrocardiography the obtained STV and LTV indices have shown significant overestimation by 10 and 50% respectively. It also turned out, that ability of clinical parameters to distinguish between normal and abnormal groups do not depend on the acquisition method. The obtained results prove that the abdominal FECG, considered as an alternative to the ultrasound approach, does not change the interpretation of the FHR signal, which was confirmed during both visual assessment and automated analysis.

show abstract

“…The Doppler echo signal reflected from moving heart is characterized by a complex structure originating from opening and closing of valves, as well as from movements of heart walls [23][24][25][26][27][28]. In addition, it is characterized by high variability in time due to fetal and maternal movements [3,29,30] and changing of transducer position in relation to a moving signal source-the fetal heart [31][32][33]. Identification of the heartbeat occurrence, based on a simple peak detection in looking for characteristic component, is very inaccurate due to its variable shape [23,34].…”

Section: Introductionmentioning

confidence: 99%

New Method for Beat-to-Beat Fetal Heart Rate Measurement Using Doppler Ultrasound Signal

Kupka

Matonia

Jeżewski

et al. 2020

Sensors

View full text Add to dashboard Cite

The most commonly used method of fetal monitoring is based on heart activity analysis. Computer-aided fetal monitoring system enables extraction of clinically important information hidden for visual interpretation—the instantaneous fetal heart rate (FHR) variability. Today’s fetal monitors are based on monitoring of mechanical activity of the fetal heart by means of Doppler ultrasound technique. The FHR is determined using autocorrelation methods, and thus it has a form of evenly spaced—every 250 ms—instantaneous measurements, where some of which are incorrect or duplicate. The parameters describing a beat-to-beat FHR variability calculated from such a signal show significant errors. The aim of our research was to develop new analysis methods that will both improve an accuracy of the FHR determination and provide FHR representation as time series of events. The study was carried out on simultaneously recorded (during labor) Doppler ultrasound signal and the reference direct fetal electrocardiogram Two subranges of Doppler bandwidths were separated to describe heart wall movements and valve motions. After reduction of signal complexity by determining the Doppler ultrasound envelope, the signal was analyzed to determine the FHR. The autocorrelation method supported by a trapezoidal prediction function was used. In the final stage, two different methods were developed to provide signal representation as time series of events: the first using correction of duplicate measurements and the second based on segmentation of instantaneous periodicity measurements. Thus, it ensured the mean heart interval measurement error of only 1.35 ms. In a case of beat-to-beat variability assessment the errors ranged from −1.9% to −10.1%. Comparing the obtained values to other published results clearly confirms that the new methods provides a higher accuracy of an interval measurement and a better reliability of the FHR variability estimation.

show abstract

Towards higher accuracy and better noise-tolerance for fetal heart rate monitoring using Doppler ultrasound

Cited by 13 publications

References 8 publications

A novel technique for fetal heart rate estimation from Doppler ultrasound signal

A novel technique for fetal heart rate estimation from Doppler ultrasound signal

Is Abdominal Fetal Electrocardiography an Alternative to Doppler Ultrasound for FHR Variability Evaluation?

New Method for Beat-to-Beat Fetal Heart Rate Measurement Using Doppler Ultrasound Signal

Contact Info

Product

Resources

About