TI-血氧与心率的采集计算

GettingStartedGuideTIDA-003011MiniaturizedPulseOximeterReferenceDesignHealthTechABSTRACTThescopeofthisdocumentistoprovideaminiaturizedpulseoximeterreferencedesignforhighendclinicalapplication.ThisreferencedesignfeaturesAFE4403,TI’shighperformanceAnalogFrontEndforpulseoximeters,anultra-lowpowermicrocontrollerandahighlyoptimizedintegratedduallightemittingdiodes(LED)andphotodiodeopticalsensor.Thisreferencedesignsimplifiesandacceleratesthepulseoximetersystemdesignwhilestillensuringthehighestqualityclinicalmeasurements.DocumentHistoryVersionDateAuthorNotes1.0June2014PraveenAroulFirstreleaseTIDA-003012Contents1DesignSummary..........................................................................................................................41.1DesignGoal............................................................................................................................41.2TopLevelArchitecture............................................................................................................42Theoryofoperation......................................................................................................................43CircuitDescription.......................................................................................................................84HardwareOverview......................................................................................................................84.1AFE4403Overview.................................................................................................................94.1.1ReceiverFrontend......................................................................................................94.1.2TransmitSection.......................................................................................................114.1.3ClockingandTimingSignalGeneration....................................................................124.1.4Diagnosticmode.......................................................................................................144.2OpticalSensor......................................................................................................................144.3Microcontroller......................................................................................................................155MiniaturizedSpO2referencedesignModules..........................................................................155.1DCM03–AFE4403modulepin-outs......................................................................................165.2DCM03–AFE4403–MCUmodulepin-outs............................................................................176VerificationandMeasuredPerformance..................................................................................196.1Testingconditions.................................................................................................................196.2EstimationofSpO2percentage.............................................................................................20AppendixA.DesignResources........................................................................................................21AppendixB.Acronyms......................................................................................................................22AppendixC.References....................................................................................................................23FiguresFigure1:TopLevelArchitecture(1)......................................................................................................4Figure2:Oxygenatedversusde-oxygenatedbloodlightabsorptionofIRandRed......................5Figure3:Variationsinlightattenuationbytissueillustratingtherhythmiceffectofarterialpulsation..........................................................................................................................6Figure4:NormalizationofRandIRwavelengthstoremovetheeffectsofvariationintheincidentlightintensityordetectorsensitivity...............................................................7Figure5:EmpiricalrelationshipbetweenarterialSaO2andnormalized(R/IR)ratio.......................8Figure6:FunctionalBlockDiagramofAFE4403...............................................................................9Figure7:TIAblockdiagramofAFE4403..........................................................................................10Figure8:LEDTransmit–H-BridgeDrive.........................................................................................13Figure9:LEDTransmit–Push-PullLEDDrive................................................................................14Figure10:DCM03Opticalsensor.....................................................................................................15Figure11:DCM03-AFE4403referencemodule................................................................................15Figure12:DCM03-AFE4403-MCUreferencemodule......................................................