A proposed novel method for CHD screening by fetal heart murmur detection using phonocardiography.

The paper presents a novel screening method to indicate congenital heart diseases (CHD) which otherwise would remain undetected because of their low level. Therefore, not belonging to the high-risk population, they are omitted from the regular fetal monitoring with ultrasound echocardiography. Based on the fact that CHDs are morphological defects of the heart causing turbulent blood flow, this turbulence appears as a murmur, which can be detected by phonocardiography (PCG). The proposed method applies measurements on the maternal abdomen and from the recorded sound signal a sophisticated processing determines the fetal heart murmur. The paper describes the problems and the additional advantages of the PCG method including the possibility of measurements at home and its combination with the prescribed regular cardiotocographic (CTG) monitoring. The proposed screening process implemented on a telemedicine system provides an enhanced safety against hidden cardiac diseases.

Screening for congenital heart diseases by murmurs using telemedical phonocardiography.

A large proportion of congenital heart diseases (CHD) remain undetected during pregnancy or even after birth. Many of them generate turbulent blood flow, resulting heart murmur. Doppler ultrasound cardiotocography (CTG) is suitable for the assessment of the fetal heart rate and some derived parameters, but it is inadequate for detecting heart murmurs. Although comprehensive examination can be carried out with echocardiography, it is expensive and requires expertise; therefore, it is not applicable for widespread screening. This paper presents a new possibility for screening for some CHDs using phonocardiography, which can be combined with Doppler ultrasound CTG as an extension of it. Furthermore it can be carried out at home allowing repeated measurements, which increases also the reliability of filtering out innocent murmurs. The diagnostic capability of this screening method is supported by a large number of evaluated fetal heart sound records. Moreover, according to experiences pregnant women prefer this reliable, easy to use method, which facilitates their examination.

Extended noninvasive fetal monitoring by detailed analysis of data measured with phonocardiography.

This paper presents a complex heuristic method for the evaluation of fetal heart sounds, applying simultaneously several algorithms, where the autocorrelation technique has been completed with the wavelet transform and the matching pursuit methods. In this way, a more reliable heart rate variability can be achieved and further parameters of the cardiac operation can be assessed in addition to the conventional cardiotocographic examination. This also comprises those parameters, which can be investigated only with long-term or continuous monitoring, and those, which rely on a very accurate estimation of the heart rate variability. The proposed method provides a way for assessing fetal heart murmurs, which is a completely new possibility for monitoring the well-being of the fetus.

Fetal phonocardiography--past and future possibilities.

The paper presents an overview of the 15 year long development of fetal phonocardiography including the works on the applied signal processing methods for identification of sound components. Based on the improvements achieved on this field, the paper shows that beyond the traditional CTG test the phonocardiography may be successfully applied for long-term fetal measurements and home monitoring. In addition, by indication of heart murmurs based on a comprehensive analysis of the recorded heart sound congenital heart defects can also be detected together with additional features in the third trimester. This makes an early widespread screening possible combined with the prescribed CTG test even at home using a telemedicine system.

A new, phonocardiography-based telemetric fetal home monitoring system.

The purpose of this article is to describe a new, phonocardiography-based fetal telemonitoring system, which, due to its passive nature, allows long-term measurements even at the home of the pregnant woman. The input element of the system was the home monitor with two sensors for recording the trans-abdominal fetal heart signal and the uterine contractions. The recorded signal was transmitted by mobile network and Internet to an Evaluation Center, where it was analyzed in detail to obtain information about possible dysfunction of the fetal heart. The investigations on this system made clear that by advanced processing of the recorded signal the system captured many additional cardiac features compared with the traditional ultrasound-based cardiotocographic procedure.