Supine PositionSkullProne PositionPatient PositioningPostureSkull BaseHeadSkull NeoplasmsSkull Base NeoplasmsSkull FracturesHead and Neck NeoplasmsTilt-Table TestHead-Down TiltHeart RateSupinationHypotension, OrthostaticGravitationNephrostomy, PercutaneousHead MovementsBlood PressureRespiratory MechanicsSkull Fracture, DepressedAutonomic Nervous SystemRespirationIndoraminParietal BoneFemur HeadValsalva ManeuverMovementPressureTomography, X-Ray ComputedSyncopeBaroreflexDizzinessSyncope, VasovagalHemodynamicsExpiratory Reserve VolumeCardiac OutputTidal VolumeTime FactorsCraniocerebral TraumaLegSudden Infant DeathReference ValuesPulmonary Gas ExchangeFluid ShiftsPalate, SoftTechnetium Tc 99m Aggregated AlbuminCranial SuturesLung Volume MeasurementsMolecular Sequence DataEsophagusEsophageal pH MonitoringPulmonary CirculationNeckMagnetic Resonance ImagingSperm HeadOxygenRestRibsSleepHead Injuries, ClosedPharynxThoracic WallBlood Flow VelocityPelvisSleep ParalysisOccipital BoneBiomechanical PhenomenaFunctional Residual CapacityImaging, Three-DimensionalCraniosynostosesInhalationLungReproducibility of ResultsBedsDiaphragmSpineAutonomic Nervous System DiseasesCarbon DioxideAirway ResistanceVentilators, Negative-PressureProspective StudiesRegional Blood FlowPlethysmographyCentral Venous PressureElectrocardiographyCephalometryAirway ObstructionPneumoperitoneum, ArtificialTongueLymphatic IrradiationEsophageal Motility DisordersVenous PressureVeinsPulmonary VentilationIntraocular PressureRespiratory MusclesJugular VeinsEquipment Design