RFID Pressure Sensor System for Hospital Mattresses to Prevent Infections and Bedsores

Bikram Virk Sujoy Sanyal

Ryan EiswerthWasif Khawaja

Mushfiq Saleheen

Dr. Koblasz, ECE4884 L05 April 22, 2008

Develop an inexpensive hospital bed mattress that can reduce the risk of bedsores and spread of Nosocomial infections.

Cost of prototype – $1,290

($1,300 less than predicted)

OVERVIEW

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Bedsores

• Definition: Unrelieved pressure to part of body for extended period of time, cutting off oxygen and blood flow

• Statistics: - 60,000 deaths/years in America - 1 million patients/year in America - 2/3 of bedsores occur in people over 70 years old

• Costs – over $1 billion/year

Life-Threatening

Life-Threatening - All Hospitalized Patients at Risk• Definition:

Hospital-Acquired Infections caused by bacteria,

viruses, etc. Includes Staph Infections• Statistics:

- more than 2 million cases/year in America

- 17,500 – 70,000 deaths/year in America• Causes:

- Sloppy hygiene: 36% preventable (CDC report)

- Aging hospitals: old mattresses

• Costs - $4.5 - $5.7 billion/year

Nosocomial Infections

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Main Components of Project

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Movement Monitoring System

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Interface Kit 8/8/8 Voltage Divider

Trossen Robotics 24” Force Sensing Resistor

WARNING: PLEASE MOVE

TIMER: 30 Min

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WARNING: EGRESS DETECTED

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• Monitor patient contact• System:

- Operating Frequency: 13.56MHz - Target Range: 24” with 1 Watt reader - Tags worn on wrist

RFID

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RFID System

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Identification Process

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WARNING: DR. SMITH PLEASE STAND BACK

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Multiplexer Design

Relays

Antennas

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Total Care SpO2RT Hospital Bed $28,500

Secure II Med/Surg Hospital Bed

$10,000

Competing Products

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Product Quantity Unit Price

Price

Movement Detection System

Trossen Robotics 24” FSR 4 $24 $80

HP Pavillion Slimline s7700e PC

1 $400 $400

Cables 1 $10 $10

RFID System

TI-FEIG RFID Reader [10] 1 $350 $350

Copper Plating 25 ft. $20 $100

Antenna Board 1 pair $100 $100

PIC Kit II Microprocessor 1 $250 $250

Total Equipment Cost $1,290

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Selling Point

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• No need to buy new beds

• Installed as add-on to existing beds

• Money saved

Current StatusSpecification Proposed Actual

RFID Reader

- Operating Frequency 13.56 MHz 13.56 MHz

- Current Draw Max. 0.5 A Max. 0.5 A

- Detectable Range 2 ft (24 in.) 1.5-1.75 ft. (18-21 in.)

Multiplexer

- Power Supply Not Proposed 3.3 V

Trossen Robotics 24” FSR

- Force Sensitivity Range <100 g to > 10 kg <100 g to > 10 kg

- Pressure Sensor Range < 1.5 psi to > 150 psi < 1.5 psi to > 150 psi

- Sensitivity to VibrationNot Significantly

AffectedNot Significantly

Affected

Allowed Patient Rest Time 30 minutes 10 seconds*

Senor Time Monitoring Every minute Every second*

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Obstacle: Proximity to Metal

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Alternative Solutions • Dynasys 13.56 MHz Antenna

• 2 foot range

• De-Q feature

• $400

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For Future Groups…

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• Buy Professionally

made antennas

• Bedside Falls

For More Information Visit Us At

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RFID Pressure Sensor System for Hospital Mattresses to Prevent Infections and Bedsores

Bikram Virk Sujoy Sanyal

Ryan EiswerthWasif Khawaja

Mushfiq Saleheen

Proximity to Metals

• Difficult to find Matching Network

• Nearby PC monitors

• PROXIMITY WITH METALS Altered performance of the RFID system can be expected when metals are in close proximity of the radiation field. Proximity to metals effectively lowers the antenna's inductance. Lower inductance causes an increase in resonant frequency and also a reduction in "Q". Designers may consider starting with a higher-than-needed "Q" "in the lab" to start with, expecting it to be lowered when it is installed in its intended location. External capacitance may be required to tune the modified antenna system back to resonance. These types of situations can be experienced around conveyor belt structures and also embedding antenna loops on concrete driveways where metal re-bar absorbs some of the radiated energy.

• http://rfidusa.com/superstore/product_info.php?products_id=121

Project Schedule

Acquire Parts 2/11/08

Construct Antennas 3/17/08

Movement Detection 3/19/08

Implement Comp. Interface 4/1/08

Implement the Full System 4/22/08

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• Bring in computer to show pressure sensors

Antenna Designs

Obstacles

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Our Design

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WARNING: EGRESS DETECTED

Desired and Actual SpecificationsSpecification Proposed Actual

RFID Reader

- Transmitting Power 1W ± 2 dB 1W ± 2 dB

- Operating Frequency 13.56 MHz 13.56 MHz

- Current Draw Max. 0.5 A Max. 0.5 A

Head-Section Antenna Dimensions

17” x 30”17” x 30”

- Detectable Range 2 ft (24 in.) 1.5-1.75 ft. (18-21 in.)

Mid-Section Antenna Dimensions

9” x 30”9” x 30”

- Detectable Range 2 ft (24 in.)

Foot-Section Antenna Dimensions

15” x 30”15” x 30”

- Detectable Range 2 ft (24 in.)

Multiplexer

- Power Supply Not Proposed

Not Proposed

Not Proposed

Trossen Robotics 24” FSR

- Force Sensitivity Range <100 g to > 10 kg <100 g to > 10 kg

- Pressure Sensor Range < 1.5 psi to > 150 psi < 1.5 psi to > 150 psi

- Sensitivity to VibrationNot Significantly

AffectedNot Significantly

Affected

Allowed Patient Rest Time (No motion)

30 minutes 10 seconds*

Pressure Senor Time Monitoring Every minute Every second*

Trossen Robotics FSR

• How it works

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In your final oral report, you should describe similar patented and

commercially available devices • Explain details about your design and

let us know why your design is better