Progresses in Fetal Monitoring by Improved Data Acquisition

Abstract

INCE the possibilities of gaining information on the fetal condition by non-invasive means are limited to only a few procedures, such as re­ cording of fetal heart action and ultra­ sonic imaging, expanding the diag­ nostic potential is a great biomedical engineering challenge. Instead of searching for new, complicated mea­ suring techniques that are often de­ clined by the medical staff, this chal­ lenge can be met by developing suitable procedures aimed at improv­ ing the analysis of data provided by present routine examinations. Car­ diotocography (CTG) is the most com­ monly used method in perinatal moni­ toring, but serious difficulties still attach to its interpretation. In many cases, an unequivocal diagnosis is not possible without first obtaining addi­ tional physiological information. The reasons may be either physiological or due to shortcomings of existing in­ strumentation. Both problems could be solved by improving the processing of available bioelectric signals, and by developing a new physiological model of the maternal influence on the fetal cardiovascular system, permitting a more reliable interpretation of the CTG. Fetal Heart Rate Recording Heart action is the only vital func­ tion of the fetus that can be recorded effectively without lesion. Conse­ quently, fetal heart rate (FHR) analy­ sis, related to uterine pressure, is the most important method in prenatal monitoring. Using non-invasive meth­ ods, heart action can be assessed by: -the electrocardiogram (ECG), picked up from the material abdo­ men,