RFID Fall Detection
Floor Mat System
Andrew Heidt
Brian Tippins
Zach Brannan
Abdirizak Mire
Coleman McDaniel
System Overview
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Detects patient falls using RFID wrist
and foot tags and an antenna
embedded in a floor mat
Provides monitoring capabilities in
hospitals and elderly care facilities,
where falls are common
Costs $3065 per unit
Design Objectives – All Met
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Reliably detect patient falls and egress
Tags reliably detected within 10” to 14” range
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Notify staff at a remote monitoring
station using a network connection
Network alerts work successfully
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Record incidents in logfile
Log file correctly documents all incidents
Technical Specifications
Proposed
Actual
Max. Read Range
12 to 24 in.
14.6 in.
Frequency Required
13.56 MHz +/- 7
kHz
13.56 MHz +/- 7
kHz
Reader Power
Requirement
> 0.75 W
1W
Mat Size
15 – 30 square ft. 12 square ft.
Weight
< 30 lbs
<15 lbs
Detection Reliability
> 95% Detection
Rate
> 95% Detection
Rate
Specification
System Diagram
Antenna Design
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Single Loop Copper
foil antenna
42 in. by 24 in.
Matched to 50 Ω
reader
Matching and Tuning Networks
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Matching Network
Input from Interface
Box
Capacitors
Common Mode
Choke
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Tuning Network
Output to Antenna
Resistor R1
Variable Capacitor C4
Jumpers
Common Mode Choke
Matching and Tuning Networks
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Matching Network
Input from Interface
Box
Capacitors
Common Mode
Choke
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Tuning Network
Output to Antenna
Resistor R1
Variable Capacitor C4
Jumpers
Common Mode Choke
VB – Computer Implementation
• Two Software Modules
1.
2.
Local Monitoring Unit - Communicate
locally with reader in/near patient room
Remote Monitoring Station - Provide
capability to monitor multiple patients at
central location
• TCP/IP Information sent includes:
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Time stamp
RFID tag ID #
Room #
Computer Interface: Process Flow
Interfacing with Hospital Network
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Local Monitoring Unit (LMU) – VB6
• Interfaces with RFID reader (Serial)
• Logs incidents to local text file
• Displays tag detection alerts
• Transmits alerts and resolutions to
remote monitoring station (TCP/IP)
Local Monitoring Unit GUI
Monitoring Window
Tag Detection
Window
Connection Window
Interfacing With Hospital Network
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Remote Monitoring Station (RMS) – VB8
• Provides patient table to aid monitoring
multiple patients
• Receives Alerts
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Determines alert type (Fall/Egress/Unknown)
Establishes relevant patient and room number
Displays alert window
Resolves remotely from LMU (TCP/IP)
Remote Monitoring Station GUI
Fall Alert
Patient Monitoring Table
Alert
Resolution
Antenna Packaging
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Antenna with anti-fatigue floor mat
Low profile floor mat ½” thickness
Antenna size 30” x 48”
Floor mat size 36” x 48” x ½”
Final Product Prototype
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Matching network circuit
Adjustable tuning
Floor mat antenna
Costs
Development Costs:
Expected Costs
Parts
Production Costs:
Actual Costs
$1000.00
Development Parts List
RFID Reader
$532.00
Floor Mat
$199.02
Copper Foil
Cables
$30.00
$118.33
Capacitors
$2.10
Resistors
$0.40
Multiplexer
$0.00
Computers
$200
RFID Tags
$15.00
Packaging
$37.00
Total
$1133.85
Parts
$1133.85
Expect Costs
Actual Costs
RFID Reader
$700.00
$532.00
Floor Mat
$100.00
$99.51
Copper Foil
$10.00
$10.00
Cables
$15.00
$40.15
Capacitors
$10.00
$0.70
$2.00
$0.20
$50.00
$0.00
$887.00
$682.56
Resistors
Multiplexer
Total
Selling Price (Based on 25% profit)
Expected Price
Selling Price
$3500.00
Actual Price
$3065.00
Results
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Proposed Read Range = 12” – 24”
Actual Read Range
• Average = 11.8”
• Peak = 14.6”
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Range is dependent on tag orientation and
location
Experimental Read Range: 0° Orientation
*Units in inches
Experimental Read Range: 45° Orientation
*Units in inches
Experimental Read Range: -45° Orientation
*Units in inches
Experimental Read Range: 90° Orientation
*Units in inches
Wrist Tag Orientation
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Due to orientation dependency, two tags
are placed on the wrist to increase read
reliability
Future Work
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Automatic tuning will allow one to
achieve maximum read range with a
changing environment
An RFID reader with a higher power
output or a larger antenna would
allow a decrease in wrist tag size
System waterproofing
Antenna embedding
Project Demonstration
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VIDEO
Patient falls cost the health care
industry $19.4 billion each year