RFID Fall Detection
Floor Mat System
Andrew Heidt
Brian Tippins
Coleman McDaniel
Zach Brannan
Abdirizak Mire
System Overview
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Detects patient falls using an RFID
wrist tag and an antenna embedded
in a floor mat
Is used in hospitals and elderly care
facilities, where falls are common
Will cost $3,500 per unit
Design Objectives
Detect patient falls and egress
< 5% detection failures
Notify staff of incidents
Record incidents in logfile
System Diagram
RFID Reader
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Feig OBID i-Scan MR101-A
Operating Frequency: 13.56 MHz
Power Output: 1 Watt
Output Impedance: 50 ohms
Floor Mat
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Built with hard tapered edges
Contains antenna structure
Placed at patient bedside
48”
3”
30”
Antenna
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Copper foil antenna
Resonant at 13.56MHz
Matched to 50 ohm reader
Antenna Design Options
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Option 1: Single-loop antenna approximately the
area of the floor mat
Option 2: Two antennas multiplexed
Single-loop
Multiplexed
Impedance Simulations (HFSS) Comparing Singleloop and Multiplexed designs
Single-loop
L= Z/(jω)=1.81 μH
Multiplexed
L= Z/(jω)=1.26 μH
Magnetic Field Simulations (HFSS) Comparing
Single-loop and Multiplexed Designs
Single-loop
Multiplexed
Summary of Antenna Design Options
Single-loop
Larger range
Low cost
Simple

Pros
Multiplexed
Smaller inductance
(easier to match)
Multiplexing adds
complexity and cost
Higher failure rate
Smaller range
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Cons
Higher inductance
(harder to match)
Computer Interface: Process Flow
Interfacing with Hospital Network
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Patient PC
• Logs incidents
• Displays fall alerts
• Transmits alerts to nurse station
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Nurse Station
• Displays fall alerts
• Adds/Removes patient information
VB – Computer Implementation
Patient PC functions:
• Listener() – listens on serial port for tag
detections
• File_Logger() – logs detection incident
with date/time in local file
• Transmit() – forwards detection
incidents and listen resets to the nurse
station
• Alert() – displays alert window on PC
VB – Computer Implementation
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Nurse Station
• Add(), Remove() – add and remove
patients from the monitoring system
• Edit() – edit patient information (name,
room number, tag number etc.)
• Ignore() – stops alerts for a specific
patient
• Alert() – displays alert window with
incident and patient information
GUIs
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Nurse Station
Patient PC
Costs
Expected Costs:
Part
Price
Updated Costs:
Part
Price
Feig Mid Range Reader
$700
Feig Mid Range Reader
$532
Floor Mat
$100
Floor Mat**
$100
Copper Foil
$10
Copper Foil
$20
Cables
$15
Cables
Capacitors
$10
Capacitors
$2
Resistors**
Resistors
Multiplexer*
$50
Total
$887
$29.35
$9.10
$2
Monitor
$120
PC
$50
Total
* - We no longer anticipate the use of a multiplexer in the design
** - Estimated Cost
$862.45
Timeline
Patient falls cost the health care
industry $19.4 billion in each year