Ante-natal monitoring of the foetal heart: A new approach on bedside computer analysis of the foetal electrocardiogram

Curran, James (1973) Ante-natal monitoring of the foetal heart: A new approach on bedside computer analysis of the foetal electrocardiogram. MD thesis, University of Glasgow.

Abstract

Perinatal mortality has not fallen so dramatically as other indices of medical care in our community. The majority of babies dying during or shortly after labour may have succumbed to factors operating in the later months of pregnancy. If these factors can be assessed antenatally such mortality may be reduced. Pregnancy is so well designed to protect the foetus that all the tools of modern technology must be applied to extract useful Information on foetal wellbeing. The foetal heart is one accessible source of such information and is an attractive focus for antenatal investigation. Most of the methods used to investigate adult cardiac performance have been applied to the foetus as a means of assessing its overall physiological condition. The following methods have been described - electrocardiography, phonocardiography, ultrasonography, ballistocardiography, impedance plethysmography and displacement cardiography. Consideration of these methods has shown that the foetal electrocardiograph (FECG) provides the most accurate basis for measurement of foetal cardiac cycle interval. Recent advances in electronic technology have made it possible to produce new FECG amplifiers at an attractive low cost. To obtain the FECG from the mother's abdomen it is necessary to cancel the superimposed maternal EGG. A simple two channel and a more complex eight channel apparatus have been designed and constructed for this purpose. A method utilising this corrected signal to construct histograms of foetal cardiac cycle intervals on a small portable computer (Nuclear Chicago 7100 C) has already been described in a previous Thesis on the FECG. A pilot study had shown that statistical measures of these histograms (e.g. mean, standard deviation, coefficient of variation) were very significant indices in foetal prognosis. An entirely new clinical trial, is presented here. 162 FECG examinations were made on hospital in-patients as a routine clinical technique and these statistical indices compared with the condition of the babies at birth as judged by the Apgar score. Statistical testing of the indices failed to reach the very high levels of significance previously demonstrated. Nevertheless the indices showed very strong trends in the expected direction on a population basis and followed the clinical course of the 25 cases where serial examinations were conducted with remarkable fidelity. A new index (standard deviation x 100/log mean) was constructed and tested. While this met theoretical requirements very closely it failed to show any practical advantage. The results of this clinical trial show that the FECG can be a practical clinical tool. It is the most accurate method for obtaining information on the foetal cardiac cycle which, particularly in serial examinations, can be of value in assessing foetal viability.

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Additional Information: Adviser: R M Kenedi
• Keywords: Medical imaging
• Date of Award: 1973
• Depositing User: Enlighten Team
• Unique ID: glathesis:1973-73954
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 14 Jun 2019 08:56
• URI: https://theses.gla.ac.uk/id/eprint/73954