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Wireless Networks of Intelligent Sensors (WISE)

Electrical and Computer Engineering Dept.University of Alabama in Huntsville

Huntsville, AL 35899

Emil Jovanov

Associate Professor

email: jovanov@ece.uah.edu

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Evolution of Computer Monitoring

processprocess Signalconditioning

Signalconditioning

Signalconditioning

Signalconditioning

Signalconditioning

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Evolution of Computer Monitoring

processprocess Signalconditioning

Signalconditioning

Signalconditioning

Signalconditioning

Signalconditioning

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Evolution of Computer Monitoring

processprocess Int.sensor

Int.sensor

Int.sensor

Int.sensor

Int.sensor

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Evolution of Computer Monitoring

processprocess Int.sensor

Int.sensor

Int.sensor

Int.sensor

Int.sensor

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Wireless Sensor NetworksNetworks of wireless sensorsData collection, distributed monitoringApplications

military/surveillance, environmental, condition based maintenanceubiquitous computingdisaster managementmedical applications Disaster Management

Condition-based maintenance

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Existing Wireless Sensor NetworksDARPA - SensITSmart Dust - University of California at Berkley

Lasers/RF for wireless communicationVery small wireless devices that can be spread, and then dynamically organize to become a sensor net

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Existing Wireless Sensor NetworksSmart Dust Communication

Infra red (IrDA)/PDAsRF 900 MHz communicationLaser communicationCorner Cube ReflectorLight Receiver Communication

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Existing Wireless Sensor NetworksUCLA

WINS (Wireless Integrated Network Sensors)Embedded processors, multihop network, sensing

Fusing physical and cognitive spacesAssess student learningPosition, orientation, acoustic data

Wireless Sensor Network (WSN)University of Tennessee, Knoxville

Small sensor scattered on or near a road, and detect enemy vehicle activity

WINS, SCADDS

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Oak Ridge National Lab

“Critters on a chip” (bioreporters)“Nose on a chip”“Lab on a chip”

DNA biochip (2D) Flowthrough genosensor (3D), etc.

Medical Telesensors (2x2 mm wireless temperature sensor)

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MedtronicDivision of Cardiology, Univ. of Western OntarioImplantable loop recorderProvides up to 14 months of cardiac monitoring40 minutes of history can be stored after an episodeWeight 17 g, volume 8 mL

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Existing Wireless Sensor NetworksMicrostrain – Wireless Web Sensor Network

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Issues

Battery lifeSizeCommunication rangeAdaptivity/RobustnessSeamless integration

Ad-hoc networksSecurity

Intelligence

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Wireless LAN Protocols

802.11b2.4GHz band, direct sequence spread spectrum

802.11a5.8GHz band, orth. freq. division multiplexing

Bluetooth900MHz & 2.4GHz bands, frequency hopping spread spectrum

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Custom Communication ProtocolsSuper Frame Timing Diagram

19 20 21 22 23 241 2 3 4 5 6 13 14 15 16 17 187 8 9 10 11 12 25 26 27 28 29 30

Slot 5Slot 4Slot 3Slot 2Slot 1

Master Slot

1st Slave

4th Slave

3rd Slave

2nd Slave

TSF

Tslot

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Intelligent medical monitors

Sudden collapse victims, result ofcirculatoryhypoxemictraumatic arrest

estimated mortality 350,000 lives/yeareconomic cost of trauma related injuries $400 billion / year (NIH PA-01-054)

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Intelligent Personal Monitors

Personal serverECG & breathing

sensors

EEG sensors

Movementsensors

Movement sensors

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Solution?

Wireless Personal Area Network of Intelligent Sensors

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Hierarchical Digital Signal Processing

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Problems of existing systems?

Development environmentcustom VLSI, assembler?

Resources for sophisticated real-time processing

memoryspeed

Price

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Wireless Personal Area NetworkWireless network of intelligent sensors

piconetworkMultiple WISE Devices and MOGULs

PERSONAL

SERVERPERSONALAREA

NETWORK

WISE

CENTRAL SITE

SERVER

INTERNET

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Initial WISE Architecture

microcontrollermicrocontroller

wireless wireless transceivertransceiver

ECG amplifierECG amplifier

ECG electrodesECG electrodes

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Wireless Intelligent Sensor WISE

BatteryMicrocontroller

TI MSP430F1498 channel 12-bit AD conv.

AccelerometerMovement detectionAnalog Device ADXL202

TransceiverLINX 916 MHz

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Wireless Intelligent Sensor WISELow power microcontroller TI430F149

16-bit RISC architecture, 60KB flash, 2KB RAMultra-low power consumption (400 µA in active mode, as low as 0.8 µA in standby mode)8 channels (12+2 bit A/D)

Wireless transceiverLINX RF transceiver 916MHz33.6 Kbps data transfer rateadjustable power/range

Biomedical amplifierTeledyne TETMD A110 (ECG/EEG amplifier)custom amplifiers

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Wireless Personal Area Network System with WISE

FixedWISE

Wireless Range ofThe MOGUL

Trajectory ofMovement

MOGUL

Mobile WISE

WirelessLink

Hierarchical Signal ProcessingInternet

Telemedicalserver

Personal Area Network

Personal networkserver

WISE

10 MIPS 10’s mWI

100MIPS 100’s mWII

500 MIPS 100’s WIII

IV

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Wireless PAN configuration

Personal WISENetwork

Personal serverECG & breathing

sensors

EEG sensors

movement sensors

Movement sensors

Internet

movementsensors

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Hierarchical DSP System Design

Constraint programmingset of constraints

Process schedulingPerformance evaluationEnergy profilingIterative process

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III µC

I Workstation

II DSP

Hierarchical process scheduling

ΙΙΙ µC

I Workstation

II DSP

Hierarchical process scheduling

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Time

Price

Power

Exploring the design space

DSPDSP

µµCC

PowerPower

Proc. TimeProc. Time

HierarchyHierarchy

BatteryBatterylifelife

samplingsamplingcyclecycle

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Wearable physiological monitors

ECG (heart activity)myocardial ischemiaarrythmiacircadian rhythm analysis of heart rate variability

EEG (brain activity)epileptic seizure detectiondrowsiness detection

Heterogenous sensors (polygraphy)sleep apnea monitoringphysical therapy feedback for stroke victimsnew generation human-computer interfaces

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Wireless PAN - Applications

Wearable physiological monitorsintelligent monitoring/early warningsdecrease hospitalizations & nursing visits

Intelligent control of medicationsensing, dosing and compliance monitoring

Aids for disabledComputer assisted rehabilitation

stroke victimssupervised heart attack rehabilitation

Battlefield soldier monitoringAdvanced human-computer interfaces

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Currently active WISE projectsWireless Heart Rate Monitor WHRMBreathing monitorPulse oxymeterUSB interfacePower aware kernelOS support for mobile codeWireless data acquisition and processingPortable physical rehabilitation

Accelerometer based monitoring position/forces

WISE Internet server

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Wireless Heart Rate Monitor WHRMDeveloped with Naval Aerospace Medical Research Lab, Pensacola, FL and RPTechnologiesArmy’s project “The War Fighter’s Stress Response”Wireless monitoring (belt), wireless uplink24 hour heart data acquisitioniPAQ PDA used as mobile gateway for data uploadEstimation of stress resistance based on Heart Rate Variability

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Intelligent data acquisition

250 Hz * 2 channels * 2B * 86400 seconds = 84 MB / day

Secondary memory

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PDA based wireless PAN

TETMD bioamplifierWireless module

LINX 916 MHz transceiver

Compaq iPAQ PDA Personal serverInternet connectivity

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Long term breathing monitor

Sensor designChest beltThermistor based differential breathing sensor

Intelligent data acquisition Wireless linkSmart card/flash memory

When_available archiving

Hierarchical processing

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Intelligent CCD Imaging SensorIVIS 1.0 Board

ImagerImagerRSRS--232 XCVR232 XCVR CPUCPU

RegulatorRegulator

SRAMSRAM

CounterCounterJTAGJTAGPortPort

RSRS--232 Port232 Port

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Dynamic Power Measurement

Dynamic power supply current measurement

Resolution 80-200 KHz, 12 bit precision

Power aware RT kernel implementationMicro C/OS II implemented

Energy per taskRealistic battery life monitoring/prediction

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Power Monitoring DeviceReal time dynamic power supply current monitoring

Power efficient computing Resolution 80-200 KHz, 12 bit precisionPower aware RT kernel implementation

Micro C/OS II implemented

Energy per taskRealistic battery life monitoring/prediction

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Emotion (Arousal) Sensing Device

GSR electrodes

Speech processing

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Situational awarenessProblems

mission critical systemslack of spatial and temporal cuesinformation overloading

SolutionPosition sensingSound beaconsprioritized warningsintegrated with command and control system

Mobile networked 3D sound systemElectronic compass

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Future WISE projects

Multimodal guidance systemElectronic compassSound beacon

GPS based control/guidance systemNew wireless communication interface

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ConclusionEnabling technology for a new generation of control&monitoring systems Sensor technology

Implantable sensors as natural extensionSingle chip intelligent sensor (“intelligent patch”)

Optimum drug administrationProlonged monitoringPortable “guardian angel”Research issues

resource allocation constraint solvingpower optimal system organization