Project Review P10011 - Motion Tracking Human Interface

Joe Piehler – Project Manager, ISE

Alex Frechette – Manufacturing Lead, ME

Dan Shields – Lead Engineer, ME

Background

Customer Nazareth Physical Therapy Clinic

Measure motion of patient System to wear out of the lab Joint Project / Continuing Project

Sensors group

Project Description

Human Interface Enclose Sensors Attach to the body

Key high level Customer needs Sanitary Portable Comfortable Durable Easy to Use

Concept Description – Hard Enclosure

4-40 Screw

Bottom Plate

Counter Sunk Holes

Concept Description – Hard Enclosure

Delrin

Filed Corners

Wire Hole

Top Piece

Screw hole with SS HeliCoil

Attachment Styles

Glue

Tape

Velcro

Tight-fitting clothing

Soft Barrier

Risk Assessment

Risk: Patient cannot move naturally while using system Would adulterate reported data Reviewed results with Customer and Advisor Mitigated during design phase by making people’s movements a design

concern

Risk: Testing phase does not occur under realistic circumstances Enclosures would not survive ‘real’ conditions Exposed enclosures to expected usage Mitigated by testing beyond overloading test conditions upon completion

to find approximate factor of safety.

Risk Assessment

Major Risk: Interfaces do not stay on patient Sensor package reports useless data

Solution Careful attention paid to making the system viable for

patients with many body types Mitigated by delivering multiple attachment styles

Current State of Design

Engineering Specifications Compression testing

Robustness Material Selection

Impact Testing Max Load

Attachment Glue Slippage

Mitigations: Soft Barrier Heli-coils Silicone Sealant

Current State of Design (cont’d) Customer Needs

Large enclosure rejected by customer Budget

Total Investment: Under $1000 Current Schedule

Flex Interference Test

Test Plan and Results

Spec Units Marginal Ideal Test Result Pass/FailWeight Ounce 3 1 2.035 Pass

Size/dimensions Inches2.375 x 2.375 x 1.125

1.125 x

1.125 x .625

0.738 x 1.311 x 1.569

Pass

Pain 0-10 1 0 1 PassCleanliness Yes or No Yes Yes Yes Pass

Time to Set Up Min 35 25 12 PassTime to remove Min 30 20 6 Pass

Enclosure Strength Lbs 50 150 5000+ PassWater Resistant Yes or No Yes Yes Yes PassInterference with current system

Yes or No No No No Pass

Drift inches 0.25 0.01 0.10 PassAttachment

strength to SkinLbs 10 25 ~5 Fail

Attachment strength to Enclosure

Lbs 10 20 ~10 Pass

Flex Interference % Change 5 2

Test Results Enclosure Strength

Normal Force: Over 5000 lbs Impact Testing: Over 500G’s

Attachment Strength Only test failure Revise specs to account for pain threshold

Time to Setup/Remove Tacky glue, toupee glue run long

Flex Interference TBD

Project was Successful!

Met Customer Needs/Engineering Specs On-Time Under Budget Integration with Sensor Team Documentation for Future Teams

Future Work

Define Ideal Attachment Strength Further System Testing Wireless Redesign

Questions?

Team Acknowledgements: National Science Foundation Dr. Sara Gombatto and the Nazareth PT Clinic Rochester Institute of Technology Dr. Beth DeBartolo, faculty advisor Dr. Sanjay Palit, advisor P10010 Group