Inspiratory CapacityInhalationPowdersPulmonary VentilationNebulizers and VaporizersRespiratory MechanicsAir PressureTidal VolumeRespirationWork of BreathingAirway ResistanceRespiratory MusclesAirway ObstructionVentilators, MechanicalNasal ObstructionDry Powder InhalersAdministration, InhalationMetered Dose InhalersRespiration, ArtificialDiaphragmBronchospirometryRegional Blood FlowRespiratory TherapyPulmonary Gas ExchangeRespiratory Function TestsPeak Expiratory Flow RateBlood Flow VelocityNosePressureAerosolsBronchodilator AgentsPositive-Pressure RespirationRespiratory Physiological PhenomenaCarbon DioxideIntercostal MusclesFlow CytometryPlethysmographyBlood Gas AnalysisSleep Apnea SyndromesLung Volume MeasurementsBreathing ExercisesIntubation, IntratrachealRespiratory InsufficiencyLungLung Diseases, ObstructiveNasal CavityEquipment DesignElectromyographySpirometryPulmonary Disease, Chronic ObstructivePharynxForced Expiratory VolumeVentilator WeaningAsthmaRespiratory SystemHumidityParticle SizeSleepHypercapniaWakefulnessOxygenPulsatile FlowAnalysis of VarianceCross-Over StudiesModels, BiologicalGene FlowStatistics, NonparametricTime FactorsAcute DiseaseCerebrovascular CirculationCoronary CirculationRheologyOptic FlowLaser-Doppler FlowmetryFlow Injection AnalysisVascular ResistanceBlood PressureMicrospheresBlood CirculationModels, CardiovascularHemorheologyMicrocirculationHydrodynamicsUltrasonography, Doppler, ColorXenon RadioisotopesPulmonary CirculationUltrasonography, DopplerCollateral CirculationLiver CirculationStress, MechanicalPerfusionCardiac OutputRenal CirculationVasodilationOxygen ConsumptionCoronary VesselsArteriesReproducibility of ResultsHeart RateBlood Volume