Processing of Doppler returns from the foetal heart: acoustic requirements for extraction of valvular timing information.
D000162:Acoustics; D004301:Doppler Effect; D004582:Electronics, Medical; D005318:Fetal Heart / Q000502:physiology*; D005323:Fetal Monitoring / Q000379:methods; D006351:Heart Valves / Q000196:embryology / Q000502:physiology; D006801:Humans; D014463:Ultrasonography