The technique and algorithms for computerized analysis of long-term fetal heart rate recordings

Objectives To describe and validate a newly developed program for the analy sis of long-term fetal heart rate (FHR) recordings. The program incorporate s the internationally, accepted analysis method described by Dawes and coll eagues and was designed to study the effects of the circadian rhythm on FHR analysis parameters. A detailed description of the analysis algorithm is p resented, never having been fully published previously. Methods The analysis program was evaluated by comparing the results of 42 F HR recordings with those of a commercially available cardiotocographic anal ysis system (Oxford Sonicaid System 8002 Team) implemented with Dawes' algo rithms. The influence of the circadian rhythm on analysis results was deter mined from 24-h recordings of 26 normal fetuses. Results No substantial differences were found in the analysts, parameters o btained between the new program: and the commercial system. Conclusion The new program offers a suitable alternative for FHR analysis e specially for scientific purposes. The possibitity of adapting the limits o f analysis and of selecting any, region: of a recording for analysis may be of great advantage when studying the temporal effects of drug treatment, e .g. in clinical pharmacology.