Supine PositionPostureProne PositionPatient PositioningGravitationLevobunololAcepromazineHeart RateRespirationMovementInteractive Ventilatory SupportRespiratory MechanicsIntra-Abdominal HypertensionTidal VolumePolysomnographyPulmonary Gas ExchangeTilt-Table TestPressureBrain ChemistryBlood PressureHead-Down TiltSleepSleep Apnea, ObstructiveIntraocular PressureBiomechanical PhenomenaBrain InjuriesOxygenSupinationHypotension, OrthostaticBrain NeoplasmsTime FactorsSleep Apnea SyndromesSwimmingNephrostomy, PercutaneousSleep, REMMolecular Sequence DataElectric ImpedanceBrain MappingAnalysis of VarianceReproducibility of ResultsElectromyographyProspective StudiesAutonomic Nervous SystemMagnetic Resonance ImagingAmino Acid SequenceIndoraminValsalva ManeuverBase SequenceBrainSyncopeBaroreflexHeadDizzinessHemodynamicsReference ValuesSyncope, VasovagalSudden Infant DeathCardiac OutputExpiratory Reserve VolumeLegRestBrain EdemaFluid ShiftsBrain StemLung Volume MeasurementsEsophagusTechnetium Tc 99m Aggregated AlbuminPalate, SoftPulmonary CirculationEsophageal pH MonitoringBrain IschemiaBlood Flow VelocityLungCarbon DioxideThoracic WallSleep ParalysisFunctional Residual CapacityBedsInhalationRibsDiaphragmPharynxRegional Blood FlowAutonomic Nervous System DiseasesCerebrovascular CirculationPlethysmographyAirway ResistanceMutationPneumoperitoneum, ArtificialVentilators, Negative-PressureCentral Venous PressurePelvisElectrocardiographyTongueTomography, X-Ray ComputedImage Processing, Computer-AssistedBlood VolumeVeinsVenous PressurePulmonary Ventilation