disposable mattress cover with wet sheet sensors ece 4884 l05 advisor: dr. art koblasz team members:...
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Disposable Mattress Cover with Wet Sheet Sensors
ECE 4884 L05Advisor: Dr. Art Koblasz
Team Members:Youn Hur
Michael WozniakPyungho Chung
Dongki Yoon
Project Overview
Improve upon previous group’s design to build a disposable mattress cover with wetness detection function
ClientHospitals, Nursing Homes, and Patient Caring Facilities
Cost$22.14 ($1.96 + $20.18)
Mattress Parts
Circuit Parts
9V DC 5V AC
or
Conductive Ink
32 gauge wire
Deviations from Previous Designs
Technical Objectives
Safe, sanitary, comfortable and durable mattress cover
Detection function to alarm wetness and breakage in conductive pattern
AC signal testing circuit
Technical SpecificationMattress Cover
Cost : Less than $2 Current
Drawn from detection circuit << 0.5 mA Dimensions Materials
Technical SpecificationDetection Circuit
Cost : Approximately $20 Current source
110V AC Dimensions (Casing)
25 cm x 20 cm x 15 cm (L x W x H) Parts
Microcontroller, Opto-isolator, Rectifier, Transformer, Resistors, Wires, Circuit board,Connector, Casing, Wall plug-in
Overall Construction
Power Adaptor
Detection Circuit Mattress PadConnector
Output of Circuit(USB, Wireless)
Computer
Mattress Conductive Pattern
Two intertwined loops to cover top surface with 10~15 cm spacing
Each loop can be checked for continuity (breakage)
AC signal sent to one loop can be read from the other loop for wetness detection
Design ApproachMicrocontroller
Low power consumption, low cost, and self-sufficient
Arithmetic logic to detect its own AC signal that runs through mattress cover
Utilize A/D converter Easy to manipulate
Design ApproachAC Signal Testing
DC changes PH level in an electrolytic solution and leads to destruction of neurons
Electricity can be detected by sense of touch at 0.5 mA (current range should be much less)
AC does not change PH and can be healing stimulant
Testing & Demonstration
Safety test Measure AC signal strength Sit on wet cover
Durability test Pull and tear to test mechanical
strength of bed sheet Fold and crumple to check breakage of
conductive pattern Run higher voltage through the circuit
Problems & Issues
Providing electrical isolation between the circuit and the mattress
Keeping cost of materials low as more parts being added
Contacting material suppliers to create the prototype is time-consuming
Project ScheduleMarch
April
2weeks 1week
3days
Analog Circuit Design
Circuit Design w/ Microcontroller
Microcontroller coding
end3/21
3/10
3/19
3/24
3/31 1week 4/7 1week
Pattern Design/Assembly
Testing
end3/28
end4/4
end4/11
Current Status
Building a prototype Building analog circuit and adjusting
components Waiting for conductive ink print on PET Writing micro-controller code