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Disposable Mattress Cover with Conductive Threads to Detect Wetness using Resistance Comparison ECE...
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Transcript of Disposable Mattress Cover with Conductive Threads to Detect Wetness using Resistance Comparison ECE...
Disposable Mattress Cover with Conductive Threads to Detect
Wetness using Resistance Comparison
ECE 4884 L03Advisor: Dr.
Koblasz
Team Members:Ankit HemaniJacob HuangYuval Rooz
Heonwoo SongSarju Vasavada
Motivation• 2 million cases of nosocomial (hospital-
acquired) infections annually (CDC)• Wet bedsheets increase risk of infection
Design Objectives• Use biodegradable plastic and paper• Stitching conductive threads on the
paper to detect wetness• Design a detection unit• Detect a break in the circuit• Detect wetness• Isolate electrical circuitry from
patient
Cost AnalysisItem PricePaper $0.65Thread $0.80Biodegradable Polyethylene $0.20Mattress Cover per unit cost $1.85
I.C.s $4.17Circuit board $4.99Encasing Box $6.99RS-232, Power jacks $10.00AC/DC Adapter $13.87Fuse, Fuse Holder $3.40Resistors, Capacitors, LED, Wires < $1.00Detection Unit cost $43.42
Layout Of Mattress Cover On Hospital Bed
Source: http://www.ponsishoes.com/products.asp
Mattress Cover Construction
• Plastic attached to paper using adhesive
• Plastic on the bottom side, paper on the top
Conductive Thread Stitching
• Conductive threads laid out on paper in two loops, of 40 ft each
• Regular threads used to stitch conductive threads on paper
Power Supply
12V AC/DC Adapter
+ TransformerFuse 9V
Regulator
• Transformer and fuse used to protect against voltage spikes
Detection Unit
Reading from mattress cover
Continuitydetection
Wetnessdetection
Opto-isolator Output
Detection Unit Schematic
Communication between Pad and Detection Unit
• Plastic clip• Four metal pads contact the
conductive loop on sheet• Wires soldered to pads connect the
clip to the detection unit
Modifications to Proposed ItemsProposed Designed Reason
Silver Thread Stainless steel More conductive
Battery Wall Outlet Cumbersome
Two Outputs One Output No need for two
Phone-jack Plastic clip Faster attachment
- Opto-isolator Safety
Current Status• Stitched a paper bedsheet (has
discontinuities)• Tested unit with a cotton bedsheet• Stitched a (non-working) paper bedsheet• Built detection unit• Designed a prototype connector
Steps for Marketable Product
• Include clip in connector• Casing for detection unit• Investigate cheaper conductive threads• Implement with full-size hospital
bedsheet nor biodegradable polyethylene
• Optimize resistances in detection unit
• If time allows, video of a project demonstration
Video
Any Questions?