Medical Applications Guide (Rev. B - Mouser Electronics

Diagnostic, Patient Monitoring and TherapyVentilation33➔Portable Respiration DeviceA portable respiration device supports a patient with the correct doseof oxygen. One pressure sensor in front of the valve measures thebreathe-in air and another one after the valve measures the breathoutpressure. A microprocessor uses the data from the two pressuresensors and single flow sensor to calculate the output of the valvethat is regulating the airflow. The medical staff can set the right airflow by a touch screen or key pad. A portable device, used in anambulance for example, has sophisticated power managementcircuitry to support mains and battery operation.Future designs will likely be equipped with a wireless datatransmission module.Further InformationPressure sensors play an important role for respiration equipment.See page 34 for a short tutorial on pressure sensing techniques andconsiderations.Other TI Components to Consider• DRV103 as valve driver• Power amplifier family OPA54x, OPA56x as valve driver• bq power management ICs for battery charging and fuel gauge• LED drivers• Low-power wireless for future designs• RS-485 (SN65HVD3082), CAN (SN65HVD251) or other interface ICsfor the communication between the sensor and controller boardACAdapterMaskChargerPowerSupplyLi-Ion CellPressureSensorFuel GaugeValveDriverµCWatchdogFlowSensorSignalConditioningADCDisplayPressureSensorLEDBacklightKeypadPortable Respiration DeviceO 2 Bottle withPressure ReducerPortable respiratory device block diagram.Texas Instruments 2Q 2007www.ti.com/medicalMedical Applications Guide