Supine PositionPostureProne PositionPatient PositioningGravitationLevobunololAcepromazineHeart RateRespirationMovementInteractive Ventilatory SupportRespiratory MechanicsIntra-Abdominal HypertensionTidal VolumePolysomnographyPulmonary Gas ExchangeTilt-Table TestPressureBlood PressureHead-Down TiltSleepIntraocular PressureSleep Apnea, ObstructiveBiomechanical PhenomenaSupinationHypotension, OrthostaticOxygenSleep Apnea SyndromesSwimmingNephrostomy, PercutaneousSleep, REMTime FactorsElectric ImpedanceMolecular Sequence DataElectromyographyReproducibility of ResultsProspective StudiesAnalysis of VarianceAutonomic Nervous SystemIndoraminValsalva ManeuverSyncopeAmino Acid SequenceBaroreflexDizzinessBase SequenceHemodynamicsSyncope, VasovagalSudden Infant DeathHeadCardiac OutputExpiratory Reserve VolumeLegFluid ShiftsReference ValuesLung Volume MeasurementsEsophagusPalate, SoftTechnetium Tc 99m Aggregated AlbuminPulmonary CirculationEsophageal pH MonitoringRestThoracic WallSleep ParalysisFunctional Residual CapacityBlood Flow VelocityLungRibsBedsInhalationDiaphragmPharynxCarbon DioxideAutonomic Nervous System DiseasesAirway ResistancePlethysmographyPneumoperitoneum, ArtificialVentilators, Negative-PressurePelvisCentral Venous PressureElectrocardiographyRegional Blood FlowTongueAirway ObstructionVenous PressureLymphatic IrradiationVeinsPulmonary VentilationEsophageal Motility DisordersRespiratory MusclesSpine