MasksLaryngeal MasksPositron-Emission TomographyOtoacoustic Emissions, SpontaneousRespiratory Protective DevicesTomography, Emission-ComputedReproducibility of ResultsIntubation, IntratrachealPerceptual MaskingEquipment DesignVehicle EmissionsFluorodeoxyglucose F18RadiopharmaceuticalsTomography, Emission-Computed, Single-PhotonTime FactorsAir PressureSensitivity and SpecificitySpectrometry, FluorescenceFiber Optic TechnologyManikinsFluorine RadioisotopesImage Processing, Computer-AssistedGreenhouse EffectDisposable EquipmentTomography, X-Ray ComputedAnesthesia, GeneralCarbon DioxideProspective StudiesEnvironmental MonitoringMagnetic Resonance ImagingBrainAlgorithmsLuminescent MeasurementsPositive-Pressure RespirationAir PollutantsReference ValuesLaryngoscopyFluorescent DyesObserver VariationPressureOxygenCarbon FootprintNitrous OxidePredictive Value of TestsMethaneEquipment Failure AnalysisFluorescenceModels, BiologicalCarbon RadioisotopesCalibrationAerosolsKineticsModels, TheoreticalAtmospherePhantoms, ImagingMultimodal ImagingRespiration, ArtificialVolatilizationAnalysis of VarianceCerebrovascular CirculationImaging, Three-DimensionalPentanesAir Pollutants, OccupationalAirTemperatureTidal VolumeAirway ObstructionInhalation ExposureComputer SimulationImage Interpretation, Computer-AssistedLung Volume MeasurementsSpectrometry, X-Ray EmissionRespiratory InsufficiencyAnesthesia, InhalationHydrogen-Ion ConcentrationTreatment OutcomeArtifactsRespirationSensory ThresholdsWaterGasesLuminescenceCricoid CartilageOptics and PhotonicsOccupational ExposureLightGasolineOxygen Inhalation TherapyProtective ClothingContrast SensitivityPhotonsFossil FuelsVolatile Organic CompoundsParticle SizeBlood Flow VelocityDramaPower PlantsCross-Over StudiesPsychophysicsLinear Models