Supine PositionPostureProne PositionPatient PositioningGravitationLevobunololAcepromazineHeart RateRespirationMovementInteractive Ventilatory SupportRespiratory MechanicsIntra-Abdominal HypertensionTidal VolumePolysomnographyPulmonary Gas ExchangeTilt-Table TestPressureBlood PressureHead-Down TiltSleepSleep Apnea, ObstructiveIntraocular PressureBiomechanical PhenomenaSupinationOxygenHypotension, OrthostaticSleep Apnea SyndromesSwimmingNephrostomy, PercutaneousTime FactorsSleep, REMElectric ImpedanceMolecular Sequence DataElectromyographyReproducibility of ResultsProspective StudiesAnalysis of VarianceAutonomic Nervous SystemIndoraminValsalva ManeuverAmino Acid SequenceBase SequenceSyncopeBaroreflexDizzinessHemodynamicsSyncope, VasovagalSudden Infant DeathHeadLegCardiac OutputExpiratory Reserve VolumeFluid ShiftsReference ValuesEsophagusLung Volume MeasurementsPalate, SoftTechnetium Tc 99m Aggregated AlbuminPulmonary CirculationEsophageal pH MonitoringRestThoracic WallSleep ParalysisFunctional Residual CapacityLungBlood Flow VelocityRibsBedsInhalationPharynxDiaphragmCarbon DioxideAutonomic Nervous System DiseasesPelvisPlethysmographyAirway ResistanceMutationPneumoperitoneum, ArtificialVentilators, Negative-PressureElectrocardiographyCentral Venous PressureTongueRegional Blood FlowVeinsAirway ObstructionVenous PressureLymphatic IrradiationEsophageal Motility DisordersPulmonary VentilationModels, MolecularSpineRespiratory Muscles