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Feb 19, 2016
Comprehensive Health Monitoring System
Comprehensive Health Monitoring System Sponsored by:
Dept. of Veterans Affairs
Samuel RodriguezDaniel ThompsonChadrick WilliamsGiselle Borrero
Physical LayoutHand UnitChest UnitWaist UnitThigh UnitSam2Project DescriptionWireless monitoring pulse oximeter, blood oxygen concentration (SpO2) and fall detectionConsists of four unitsReceiving Display unit (RDU)3 Transmitting Sensor Units (TSU)All units will be worn by the patientFinger sensor will obtain pulse and SpO2 and transmitChest and thigh sensor will determine patients posture informationWaist display will receive data, display data, and transmit emergency signals Sam3GoalsUltimately to monitor patients for chronic heart and related health conditionsRemotely contact emergency services Provide location to emergency services of patient More affordable than existing wireless unitsIdeal for a variety of usersMaximum protection at minimal to no cost Sam4ObjectivesTransmitting Sensor Units (TSU)To be worn on the finger, wrist, chest and right thighBattery poweredControl the pulse oximeter sensorMake calculations to achieve pulse and oxygen concentration dataDetermine the posture of the patientMeasure patients angular velocity and accelerationMonitor units battery lifeTransmit data wirelessly to the waist unit (RDU)
Receiving Display Unit (RDU)Receive data wirelessly from TSUsDisplay patients pulse and oxygen concentrationContact emergency servicesMonitor units battery lifeAudible and visual alerts for critical conditions, loss of signal and battery life, and display personal informationSam5Pulse OximeterNon-invasive optical measurement of heart rate and blood oxygen saturation Hemoglobin is the red colored substance in blood and is the carrier of oxygenRed and infrared light are attenuated less by the body tissues and more by blood (600nm, 940nm)Light shines through finger and strikes a photodiode, which creates a very small current based on the amount of light incident on the photodiodeThis determine attenuation of light based on the output of the photodiode
Sam6SensorGenerate alternating pulses of light at 600nm (red) and 940nm (infrared)Photodiode must detect light in the range of 600nm to 940nmConvert photodiode current to voltages values between 0V to 2.3VAccuracy of 2% (70% - 100%)2 BPM for pulseTransmit a maximum of 10 ftMCUTwo DACs 12-bitsThree ADCs 12-bits12 GPIOsPulse Oximeter DesignSam7 Pulse Oximeter Subsystem
Sam8To calculate pulse oximetry the photodiode current must be converted to a voltageThis voltage has both a DC and AC component that represents attenuation of lightDC-constant volume of blood used for auto gain controlAC ebbing and flowing of blood used for measurementsPulse-Ox Sensor
Sam9Control alternating pulses by pair of LED select lines (STG3155)Common power linesDAC controls current through system to avoid damage to LEDsSensor Control
Sam10Automatic Gain ControlSam11TSU Pulse Oximeter
Pulse OximeterChest and Thigh Fall Detection DesignDetermine the patients position (sitting, standing or laying down)Measure angular velocity and acceleration of patientHave a range of 6g acceleration.Have an accuracy of angular velocity between 300/s to 500/sHave a sampling rate of at least 120Hz
Consist of:Two 3-axis gyroscopes (ITG-3200)Two 3-axis accelerometers (MMA7631L)One of each in the center of the chest and right thighMCU MSP430FG438Three 12-bit ADCs34 GPIOsRF Transceiver CC1101Fall Detection Design
Fall Detection Block Diagram
TSU Fall Detection
TSU Fall DetectionRF transponder receives information from peripheral unitsMulticontroller stores past data and makes decisions about patient status16x2 LCD displays patient information, alerts, emergencies, or system statusBuzzer and LEDs provide visual and auditory stimulus for alertsRDU DesignDaniel19Waist Block Diagram(Receiving Display Unit)
Waist SchematicPart numberComponent size (mm2)Number of I/O pinsExtra built-in featuresCost($) JN51488 x 8212.4GHz transceiver, 12-bit ADC, 12-bitDAC, 4 wire audio interface20CC4309 x 932 - 64Sub 1GHz transceiver, 12-bit ADC, CC11015.00*MSP430F23312 X124812-bit ADC2.50*MSP430F261612 x 12 or 14 x1448 or 6412-bit ADC, 12-bit DAC, DMA controller5.85*MSP430FG43714 x 144812-bit ADC, 2x 12-bit DAC,3x Op Amps, Analog comparator, DMA, SVS, LCD driver 5.15*MulticontrollerDaniel23Separate unit from the MCUBuilt-in display controllerMay display pulse, blood oxygen content, patients name, or alarm informationLiquid Crystal Display
MCU LCD controller had too few segments; would take too many pin outs.24Green LED- Blinks if a fall is detectedBlue LED- Blinks if RDU loses signal from peripheralsRed LED- Blinks if emergency is active or user has indicated panicPiezoelectric Buzzer- Pulses if emergency is active
Alert ProtocolDaniel25All units powered by a battery, through a DC/DC buck converter2.5V supply to Gyroscope logic3.3V supply to MCU, RF transceiver, and all sensor units5V supply to LCDBattery voltage monitored by built-in comparator in the MSP430FG43xPower ManagementDaniel263.3V output supplies MCU and sensors, and another buck converter supplies 5V for the LCD anodeBuck DC/DC converter
Analog to digital converter internal to MCUOutput to Red-Yellow-Green LEDVoltage divider from battery, scaled with the MCUs maximum input voltageBattery Life Monitoring
Development Environments Language: C, JAVA
Testing: DevC++ V 22.214.171.124
Implementation: Code Composer Studio V4.2.1.00004, eclipse
Schematics: Cadsoft EAGLE V 5.11.0
ChadSimpliciTI = simple low-power RF network protocol aimed at small RF networks.Code Composer Studio instead of IAR because of familiarity with environment29Development KitMSP-FET430UIFEM430F6137RF900
Chad36Fall Detection Algorithm
Accurate, Fast Fall Detection Using Gyroscopes and Accelerometer-Derived Posture Information
The recommended thresholds are influenced by a persons profile (e.g. height, weight, age.)
37Fall Detection - Acceleration Sample OutputThe linear acceleration and rotational rate of the chest and thigh for:StandingWalkingSittingRunning
The uses-permission function is needed in order to use Bluetooth features in any application. This is required to perform different types of communication such as requesting and accepting connections, and transferring data.
The mBluetoothAdapter function is needed for any and all Bluetooth activity. It represents the Bluetooth adapter, or Bluetooth radio, and is used for the entire system.
The REQUEST_ENABLE_BT function is to ensure that the Bluetooth is enabled. If the Bluetooth on the device is set off, this function prompts the user to enable Bluetooth through the system settings without stopping the application. Bluetooth;mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
The startDiscovery() function searches and scans for other dvices. The scanning of devices takes about 12 seconds to complete and scans constantly.
The REQEST_CONNECT_DEVICE function is needed to actually connect to two devices. This is enabled by using the Bluettoth service socket which accepts a connection request and performs the connection.
The callIntent function allows the android application to make a phone call. The number is preset is this function.
BudgetSubsystemWaist$77.20Chest$75.98Hand$36.50Thigh$75.98Design$438.24Total$703.89SubsystemWaist$90.72Chest$70.98Hand$54.39Thigh$70.98Design$199.00Total$486.07Original budgetFinal BudgetQuestions?Giselle43