Untersuchung der fetalen Herzfrequenz mit Methoden der Komplexitätsanalyse

The fetal heart rate is influenced by a multitude of parameters and therefore shows typical fluctuations enabling the experienced physician, by means of a CTG, to analyse the cardio-vascular system of the fetus and to judge its ability to cope with stress during birth. Several randomized studies have shown, however, that the antenatal CTG has limited prospective value; in particular the incidence of false - positive results of CTG evaluations has been found to be inacceptably high. New methods of evaluating fetal heart rate tracings are being sought which should reduce unnecessary Cesarean sections by better recognizing the fetuses truly at risk. It has been shown that a system as complex as a cardiovascular system can best be described by complexity analysis and that a healthy system demonstrates greater variability in the heart rate and thus more "chaotic" behavior than a compromised one: "Loss of this chaotic nature ... is immediately preceding death." 10 Methods of complexity analysis are highly sensitive mathematical procedures. Since real variations of fetal heart rate and recording errors are equally processed by the computer, careful attention has to be paid to the quality of the heart rate tracing and the proper conversion of data. Careful selection of embedding dimensions is crucial in complexity analysis, especially for the results of quantitative analysis (LLE, STE), whereas the results of qualitative methods such as Recurrence Plot and 3D-Plot do not necessarily appear to be highly dependent on embedding dimensions. Of the analysis methods evaluated here, histogram and recurrence histogram as well as spatio-temporal entropy did not provide satisfactory predictions as to fetal well-being after birth. The benefit of determining the Largest Lyapunov Exponent was limited by its sensitive dependence on embedding dimensions, though a correlation with fetal well-being was demonstrated, whereas the evaluation of correlation dimension D2 as well as 3D-Plots provided encouraging results and seems to be robust and usable. Therefore the evaluation of correlation dimension and 3D-Plots as well as qualitative assessment of recurrence plots deserve further study in the quest for a more predictive analysis of the fetal heart rate.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2002

Author dc:creator

• Wassenberg, Barbara

Contributors dc:contributor

• Jörn, Hendrik Horst

• info:eu-repo/classification/ddc/610
• Medizin

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-119121%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:57051