Fourier AnalysisSpectrum AnalysisHeart RateSignal Processing, Computer-AssistedUltrasonographyUltrasonicsElectroencephalographyHeartAlgorithmsAutonomic Nervous SystemElectromyographyTime FactorsBlood PressureElectrocardiographyHeart Rate, FetalSympathetic Nervous SystemHeart FailureRadiographic Image EnhancementSpectrum Analysis, RamanWakefulnessPhantoms, ImagingPostureRadiographic Image Interpretation, Computer-AssistedPropofolHeart DiseasesStochastic ProcessesAction PotentialsHeart TransplantationModels, NeurologicalReproducibility of ResultsHeart Defects, CongenitalArtifactsMuscle FatigueNonlinear DynamicsHemodynamicsModels, TheoreticalLocus CoeruleusSleepFetal HeartPeriodicityComputer SimulationSensitivity and SpecificityMathematicsMammographyPhotic StimulationElectrocardiography, AmbulatoryBaroreflexImage Processing, Computer-AssistedMuscle, SkeletalHeart Atria