title: Electrocortical activity in the near-term ovine fetus: automated analysis using amplitude frequency components.
abstract: We have designed an automated method for analyzing electrocortical (ECoG) activity in the near-term ovine fetus to process and quantitatively classify large amounts of data rapidly and objectively. Seven chronically catheterized fetal sheep were studied for 8h each at ~0.9 of gestation with continuous recording of ECoG activity using a computerized data acquisition system. Multiple ECoG amplitude and frequency parameters were scored from which we established animal specific parameter cut-off values as well as population based duration cut-off values to distinguish low-voltage/high frequency (LV/HF) and high-voltage/low frequency (HV/LF) state epochs, and indeterminate voltage/frequency (IV/F) and transition period activities. We have shown that the incidence of the predominant LV/HF and HV/LF activity states at 45% and 36% of the time, respectively, is comparable to that previously reported using semi-quantitative techniques with visual analysis. However, the duration of these state epochs is considerably shorter due to the detection of brief periods of IV/F activity which would be difficult to capture using visual analysis. Importantly, our findings in the healthy ovine fetus near-term using this automated ECoG scoring methodology now provide a framework from which to study maturational events in younger animals, and under adverse pregnancy conditions.
authors.affiliation: Department of Obstetrics and Gynaecology, The Canadian Institutes of Health Research Group in Fetal and Neonatal Health and Development, Children's Health Research Institute, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Ashley E
authors.initials: AE
authors.lastname: Keen
authors.forename: Martin G
authors.initials: MG
authors.lastname: Frasch
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Sheehan
authors.forename: Brad J
authors.initials: BJ
authors.lastname: Matushewski
authors.forename: Bryan S
authors.initials: BS
authors.lastname: Richardson
mesh_terms: D000818:Animals; D058256:Brain Waves / Q000502:physiology*; D002540:Cerebral Cortex / Q000196:embryology* / Q000502:physiology*; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005323:Fetal Monitoring / Q000295:instrumentation / Q000379:methods*; D005333:Fetus / Q000502:physiology*; D011247:Pregnancy; D011930:Reaction Time / Q000502:physiology; D012756:Sheep; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013997:Time Factors