On processing of Doppler returns from the foetal heart: an electronic processing method for extraction of valvular timing information.
D001021:Aortic Valve / Q000502:physiology; D004301:Doppler Effect; D005318:Fetal Heart / Q000502:physiology*; D005323:Fetal Monitoring / Q000379:methods*; D006801:Humans; D055585:Physical Phenomena; D010825:Physics; D014465:Ultrasonics