A windows application for real-time fetal ECG analysis

A systematic scoping review to identify the design and assess the performance of devices for antenatal continuous fetal monitoring

BACKGROUND

Antepartum fetal monitoring aims to assess fetal development and wellbeing throughout pregnancy. Current methods utilised in clinical practice are intermittent and only provide a 'snapshot' of fetal wellbeing, thus key signs of fetal demise could be missed. Continuous fetal monitoring (CFM) offers the potential to alleviate these issues by providing an objective and longitudinal overview of fetal status. Various CFM devices exist within literature; this review planned to provide a systematic overview of these devices, and specifically aimed to map the devices' design, performance and factors which affect this, whilst determining any gaps in development.

METHODS

A systematic search was conducted using MEDLINE, EMBASE, CINAHL, EMCARE, BNI, Cochrane Library, Web of Science and Pubmed databases. Following the deletion of duplicates, the articles' titles and abstracts were screened and suitable papers underwent a full-text assessment prior to inclusion in the review by two independent assessors.

RESULTS

The literature searches generated 4,885 hits from which 43 studies were included in the review. Twenty-four different devices were identified utilising four suitable CFM technologies: fetal electrocardiography, fetal phonocardiography, accelerometry and fetal vectorcardiography. The devices adopted various designs and signal processing methods. There was no common means of device performance assessment between different devices, which limited comparison. The device performance of fetal electrocardiography was reduced between 28 to 36 weeks' gestation and during high levels of maternal movement, and increased during night-time rest. Other factors, including maternal body mass index, fetal position, recording location, uterine activity, amniotic fluid index, number of fetuses and smoking status, as well as factors which affected alternative technologies had equivocal effects and require further investigation.

CONCLUSIONS

A variety of CFM devices have been developed, however no specific approach or design appears to be advantageous due to high levels of inter-device and intra-device variability.

The feasibility of long-term fetal heart rate monitoring in the home environment using maternal abdominal electrodes

It is well established that fetal and maternal electrocardiograms (ECGs) can be obtained from the maternal abdomen using standard surface electrodes, although this cannot be guaranteed. The unobtrusive and non-invasive nature of such monitoring lends itself naturally to the long-term ambulatory collection of this data on cardiac activity. By employing suitable algorithms it would then be possible to extract records of both fetal and maternal heart rate. This article presents results of the collection of raw electrophysiological signals, containing both fetal and maternal ECGs from a single volunteer from the 20th week of gestation until term. The significance of the data is that they were recorded by the mother herself in her own environment. Previously written software was then used to extract fetal and maternal heart rate data. These results demonstrate the feasibility of using this method for the long-term recording of fetal and maternal heart rate in the mother's normal surroundings.