1. RFID Fall Detection Floor Mat System
Andrew Heidt
Brian Tippins
Coleman McDaniel
Zach Brannan
Abdirizak Mire

2. System Overview
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

3. Design Objectives Detect patient falls and egress
< 5% detection failures
Notify staff of incidents
Record incidents in logfile

4. System Diagram

5. RFID Reader Feig OBID i-Scan MR101-A Operating Frequency: 13.56 MHz
Power Output: 1 Watt
Output Impedance: 50 ohms

6. Floor Mat Built with hard tapered edges Contains antenna structure
Placed at patient bedside
48” 3”
30”

7. Antenna Copper foil antenna Resonant at 13.56MHz
Matched to 50 ohm reader

8. Antenna Design Options
Option 1: Single-loop antenna approximately the area of the floor mat
Option 2: Two antennas multiplexed
Single-loop
Multiplexed

9. Impedance Simulations (HFSS) Comparing Single-loop and Multiplexed designs
L= Z/(jω)=1.81 μH
L= Z/(jω)=1.26 μH

10. Magnetic Field Simulations (HFSS) Comparing Single-loop and Multiplexed Designs

11. Summary of Antenna Design Options
Single-loop
Multiplexed
Pros
Larger range
Low cost
Simple
Smaller inductance (easier to match)
Cons
Higher inductance (harder to match)
Multiplexing adds complexity and cost
Higher failure rate
Smaller range

12. Computer Interface: Process Flow

13. Interfacing with Hospital Network
Patient PC
Logs incidents
Displays fall alerts
Transmits alerts to nurse station
Nurse Station
Adds/Removes patient information

14. 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

15. VB – Computer Implementation
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

16. GUIs
Nurse Station
Patient PC

17. Costs Expected Costs: Updated Costs:
Part
Price
Feig Mid Range Reader
$700
Floor Mat
$100
Copper Foil
$10
Cables
$15
Capacitors
Resistors $2
Multiplexer*
$50
Total
$887
Part
Price
Feig Mid Range Reader
$532
Floor Mat**
$100
Copper Foil
$20
Cables
$29.35
Capacitors
$9.10
Resistors** $2
Monitor
$120 PC
$50
Total
$862.45
* - We no longer anticipate the use of a multiplexer in the design
** - Estimated Cost

18. Timeline

19. Patient falls cost the health care industry $19.4 billion in each year