Smart Mattress

Bryan Kuo, Priyen Patel, Dev Shah, Xitij Shah, Tim Stamm

Georgia Institute of TechnologyOctober 23, 2008

Project Overview

Goals: Prevent bedsores acquired on hospital/nursing home beds

Wetness DetectionInactivity Detection

Prevent incorrect medication administrationPatient Identification SystemPatient Barcode Display

Clients: Hospitals Nursing Homes

Cost: $1,600

Design Objectives

Identify patients using RFIDDisplay patient information and barcode

on a PC monitorDetect moisture and patient inactivity that

could cause bed soresAlert staff if patient is in danger of

developing bed sores

Overall System - Current

RFID System

RFID antenna located at foot of bedDynasys RFID tags on patients’ anklesPatient tag compared to patient ID databasePatient name and barcode displayed on PC

RFID Tag and Antenna Reader HP Slimline PC

RFID System

OBID i-scan HF RFID Reader OBID i-scan HF Pad Antenna RFID Operating Frequency: 13.56 MHz RFID Antenna Range: 7 in. RFID Transmitting Power: 1W ± 2 dB

* Note: This range may not meet specification requirements

Inactivity Monitoring System

Inactivity Monitoring System

Wetness Detection

Conductive thread connected to wetness detection circuit

1st comparator monitors moisture

2nd comparator detects breaks in conductive tape

Wetness Detection System

From Prototype to Final Design

PIC Microcontroller

Low power operation using 3V coin cell battery and PIC18F2321

Programmed in C via 6-pin header through PICkit2 using MPLAB IDE

RS232 communication to PC using onboard UART

Pushbutton and LED for debugging

PIC for Final System Implementation

Inactivity monitoring Sample force sensing resistors using

onboard ADC Wetness detection

Sample output of comparators using digital input

Phidgets cost ~$110 versus ~$30 for PIC system

Current Status

Wetness detection circuit Implemented on breadboard 2 comparators and 3V battery power supply Output tested with multimeter

Inactivity monitoring system 4 Trossen Robotics force sensing resistor strips with Phidget

voltage dividers Sampled with Phidget 8/8/8 Interface Kit and center of mass

calculated using Visual C# RFID System

Tested preliminary reader and tag functionality Have demonstrated software control in Visual C#, but still

needs further refinement

Demonstration Plan

Inactivity Detection Group member lays for extended period of time. LCD monitor displays inactivity alarm

Patient Identification RFID tag located within antenna range LCD monitor displays patient name LCD monitor displays patient medication barcode

Wetness Detection Salt water poured on bed LCD monitor displays wetness alarm

Project Schedule

Acquire Parts 9/19/08

Start Testing Wetness Detection 10/19/08

Start Testing Inactivity Monitor 10/19/08

Develop RFID System 11/10/08

Develop Graphical Display 11/15/08

Develop PCB 11/20/08

Implement the Full System 11/30/08

QUESTIONS?