Post on 12-Sep-2021
transcript
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Portable Telemedical MonitoringUsing Wireless Sensors
on the Edge of the Internet
University of Alabama in HuntsvilleElectrical and Computer Engineering Dept.
Huntsville, AL 35899
Emil Jovanov
email: jovanov@ece.uah.edu
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Intelligent monitors
• Sudden collapse victims, result ofl circulatoryl hypoxemicl traumatic arrest
• estimated mortality 350,000 lives/year• economic cost of trauma related injuries
$400 billion / year (NIH PA-01-054)
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Intelligent Personal Monitors
Personal server
ECG & breathing
sensors
EEG sensors
Movementsensors
Movement
sensors
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Can we make it without wires?
• Wireless infrastructurel 700 million subscriber units by 2002
• Mobile computingl system on chip
• Intelligent wireless sensors• Intelligent health monitors / warning devices• Personal Area Network (PAN)
l body network / intelligent clothesl wireless personal area networkl hierarchical processing
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Solution?
Wireless Personal Area Network ofIntelligent Sensors
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Hierarchical Digital Signal Processing
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Problems of existing systems?
• Development environmentl custom VLSI, assembler?
• Resources for sophisticated real-timeprocessingl memoryl speed
• Price
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Wireless Personal Area Network
• Wireless network of intelligent sensors• Wireless Intelligent Sensor (WISE)
Internet
Telemedical server
PANPersonal networkserver
WISE
• Piconetwork• Sensors
l EEGl ECGl breathingl movement
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Wireless Intelligent Sensor WISE• Low power microcontroller TI430F149
l 16-bit RISC architecture, 60KB flash, 2KB RAMl ultra-low power consumption (400 µA in active
mode, as low as 0.8 µA in standby mode)l 8 channels (12+2 bit A/D)
• Wireless transceiverl LINX RF transceiver 916MHzl 33.6 Kbps data transfer ratel adjustable power/range
• Biomedical amplifierl Teledyne TETMD A110 (ECG/EEG amplifier)l custom amplifiers
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WISE Architecture
microcontrollermicrocontroller
wireless wireless transceivertransceiver
ECG amplifierECG amplifier
ECG electrodesECG electrodes
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WISE Ver. 1.2
microcontrollermicrocontroller
wireless wireless transceivertransceiver
ECG amplifierECG amplifier
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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 server
ECG & breathingsensors
EEG sensors
movement sensors
Movement sensors
Internet
movementsensors
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Hierarchical DSP System Design
• Constraint programmingl set of constraints
• Process scheduling• Performance evaluation• Energy profiling• Iterative process
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Process scheduling issues
• System parametersl execution timel energy per processl communication
• Constraint based scheduling
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System Implementation
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Trace
collectionMODULES
Module_n
Module_2
Module_1
Compiler_n
Compiler_2
Compiler_1
SYSTEM
Ln
L2
L1
PreprocessorConfiguration
file
Ln
L2
L1
Constraints
file
Constraint
solver
Trace
file
Application
source code
ΙΙΙ µC
I Workstation
II DSP
Hierarchical process scheduling
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Environment for dynamic energy profiling
Jovanov, et al., “Jovanov, et al., “Environment for Energy Profiling of DSP Applications”, ICSPAT 2000, Dallas, TX.Environment for Energy Profiling of DSP Applications”, ICSPAT 2000, Dallas, TX.
DSP Application Profiling Example
CF ActiveCF ReadCPU Active
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Time
Price
Power
Exploring the design space
DSPDSP
µµµµCC
PowerPower
ProcProc. Time. Time
HierarchyHierarchy
BatteryBatterylifelife
samplingsamplingcyclecycle
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Examples
• ECG analysis (ischemic event monitor)• Activity monitor• Breathing monitor• Civil Disaster Data Acquisition Device
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ECG Analysis
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• Sophisticated analysis in real timel High performance/low power DSP
• Warnings (sometimes life saving)• Typical ECG processing algorithms
l Initialization (thresholds, polarity, gain control)l Filtering (band pass filters, notch filters)l QRS complex detectionl Heart rate variability processingl Baseline correction
• Robust algorithms
ECG analysis
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ECG Holter Development Environment
Keyboard Input
ECGamplifier
AD
LCD Output
TMS320C5410DSP
DA
Compact FlashInterface
Programmable Logic
CompactFlash
Memory Card
AIC
SerialInterface
PC/Workstation
Speaker/Headphones
512Kx16Flash
Microphone
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Hierarchical processing issues
• Data mining on higher levels• Adaptive thresholds• Multi-sensor synergyl running/sitting?
• Environmental effects
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User activity monitoring
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Accelerometer basedWireless Intelligent Sensor
• Analog Devices ADXL 202/210 MEMS• Digital front-end of WISE
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Alternative processing methods
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Breathing sensor
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Breathing sensor• Custom analog front end• Thermistor based differential breathing sensor
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Circadian breathing rhythm analysis• Wireless link• When_available archiving• Hierarchical processing
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ECG system setup and monitoring
• System setup & debugging• Visual Basic application on portable computer• WISE Gateway with serial link interface
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Wearable physiological monitors
• ECG (heart activity)l myocardial ischemial arrythmial circadian rhythm analysis of heart rate variability
• EEG (brain activity)l epileptic seizure detectionl drowsiness detection
• Heterogenous sensors (polygraphy)l sleep apnea monitoringl physical therapy feedback for stroke victimsl new generation human-computer interfaces
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Wireless PAN - Applications
• Wearable physiological monitorsl intelligent monitoring/early warningsl decrease hospitalizations & nursing visits
• Intelligent control of medicationl sensing, dosing and compliance monitoring
• Aids for disabled• Computer assisted rehabilitation
l stroke victimsl supervised heart attack rehabilitation
• Battlefield soldier monitoring• Advanced human-computer interfaces
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Conclusion• Enabling technology for a new generation of
telemedical systems and intelligent sensors• Sensor technology
l Implantable sensors as natural extensionl glucose blood monitors, drug pumps
• Optimum drug administration• Prolonged monitoring• Portable “guardian angel”• Research issues
l resource allocationl constraint solvingl power optimal system organization
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Acknowledgments
• Dejan Raskovic• John Price• John Chapman• Anthony Moore• Abhishek
Krishnamurthy
DSP ChallengeDSP Challenge Student projectsStudent projects• Lou Woods• Daniel Pritchett• Sergey Dergunov• Dejan Milutinovic
CollaboratorsCollaborators• Dr. Krishna Kavi• Dr. Tom Martin