Supine PositionPostureProne PositionPatient PositioningGravitationLevobunololAcepromazineHeart RateRespirationMovementInteractive Ventilatory SupportRespiratory MechanicsIntra-Abdominal HypertensionTidal VolumePolysomnographyPulmonary Gas ExchangeTilt-Table TestPressureBlood PressureHead-Down TiltSleepSleep Apnea, ObstructiveIntraocular PressureBiomechanical PhenomenaSupinationHypotension, OrthostaticOxygenSleep Apnea SyndromesSwimmingNephrostomy, PercutaneousSleep, REMElectric ImpedanceTime FactorsMolecular Sequence DataElectromyographyReproducibility of ResultsAutonomic Nervous SystemAnalysis of VarianceProspective StudiesIndoraminValsalva ManeuverSyncopeBaroreflexAmino Acid SequenceDizzinessBase SequenceHemodynamicsSyncope, VasovagalSudden Infant DeathHeadCardiac OutputExpiratory Reserve VolumeLegFluid ShiftsLung Volume MeasurementsPalate, SoftReference ValuesEsophagusTechnetium Tc 99m Aggregated AlbuminPulmonary CirculationEsophageal pH MonitoringRestThoracic WallSleep ParalysisFunctional Residual CapacityBlood Flow VelocityRibsBedsInhalationLungDiaphragmPharynxCarbon DioxideAutonomic Nervous System DiseasesPlethysmographyAirway ResistancePneumoperitoneum, ArtificialVentilators, Negative-PressureCentral Venous PressurePelvisElectrocardiographyTongueRegional Blood FlowVenous PressureLymphatic IrradiationAirway ObstructionEsophageal Motility DisordersVeinsPulmonary VentilationRespiratory MusclesSpine