A Proposed Phonography-Based Measurement of Fetal Breathing Movement Using Segmented Structures with Frequency Splitting

This paper proposes a detection method of fetal breathing movement (FBM) as an important data of fetal well-being. To analyze the chaotic nature of the individual episodes, the frequency band has been split into single test frequencies in order to find its starting point (SP) as a signal free (quiet) zone. Computing some features of the signal the sound will be distinguishable from the disturbing signals as hiccups, body's rotation and limb movements or even additional noises of maternal heart beats. The SPs of the episodes are characterized by an approximation process in order to select the real ones.Clinical relevance- The method is an irradiation free measurement, carried out on the maternal abdomen. Furthermore, connected with the fetal phonocardiographic (fPCG) monitoring the method offers a non-invasive way for FBM detection applicable also at home. More than 50 pregnancies were examined with the proposed method for at least for 20-min with synchronous measurements by the proposed phonographic device and a 3D ultrasound machine in the third trimester.

Experiences with fetal phonocardiographic telemonitoring and future possibilities

Phonocardiography (PCG) makes possible the examination of some fetal cardiac anomalies which otherwise usually remain undetected during pregnancy. The application of PCG in a telemonitoring system enhances its diagnostic capabilities, allowing long-term measurements even at home. The paper summarizes the intensive fetal monitoring campaign carried out in Hungary during the last three years that yielded useful experience regarding recent and future possibilities of fetal monitoring. Results collected from a large number of measurements suggest that PCG home monitoring may be a suitable screening method for fetal congenital heart diseases, even if surgical intervention in this phase of pregnancy is not easy.

Long-term Phonocardiographic Fetal Home Monitoring for Telemedicine Systems

A novel compact method for fetal home monitoring optimized for long data acquisition time and low communication costs is presented. The method incorporates the preprocessing of disturbed acoustic signal received on the maternal abdomen. The basic idea of the preprocessing is that the detection of the systolic and diastolic sounds takes place on two separated frequency bands with autocorrelation on predicted time intervals. Measurements on 47 selected pregnant women have shown that the use of this method significantly reduces the amount of data to be transferred to the computer centre in the hospital, where only the very disturbed time periods have to be evaluated. Based on this method a new, phonocardiographic fetal telemedicine system can be built without time limitation of measurements.