Sleep StagesSupine PositionSleepSleep, REMProne PositionPolysomnographySleep DisordersWakefulnessPosturePatient PositioningSleep Apnea SyndromesElectroencephalographySleep Apnea, ObstructiveArousalElectrooculographyNocturnal Myoclonus SyndromeHeart RateCircadian RhythmSignal Processing, Computer-AssistedSleep Apnea, CentralRespirationAutonomic Nervous SystemDelta RhythmSleep Initiation and Maintenance DisordersSleep DeprivationTilt-Table TestTime FactorsElectromyographyHead-Down TiltSupinationHypotension, OrthostaticReference ValuesOxygenNephrostomy, PercutaneousGravitationBlood PressureRespiratory MechanicsBody TemperatureElectrocardiographySleep ParalysisNonlinear DynamicsSeverity of Illness IndexAnalysis of VarianceReproducibility of ResultsIndoraminSnoringValsalva ManeuverPressureBaroreflexSudden Infant DeathPalate, SoftSyncopeMovementDizzinessHemodynamicsTidal VolumeExpiratory Reserve VolumeSyncope, VasovagalPharynxCardiac OutputFluid ShiftsPulmonary Gas ExchangeActigraphyLegBedsRestLung Volume MeasurementsEsophagusAirway ResistanceEsophageal pH MonitoringInhalationTechnetium Tc 99m Aggregated AlbuminPulmonary CirculationHeadPulmonary VentilationAirway ObstructionBrainCarbon DioxideTongueDisorders of Excessive SomnolenceDiaphragmFunctional Residual CapacityProspective StudiesThoracic WallVentilators, Negative-PressurePlethysmographySleep BruxismBlood Flow VelocityAutonomic Nervous System DiseasesRespiratory MusclesRibsLungSleep Disorders, Intrinsic