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

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

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

System Diagram

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

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

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

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

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

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

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

Computer Interface: Process Flow

Interfacing with Hospital Network Patient PC Logs incidents Displays fall alerts Transmits alerts to nurse station Nurse Station 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 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 Nurse Station Patient PC

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

Timeline

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